CHEMICAL HYGIENE PLAN
Clemson University
2009
Prepared by: Naomi Kelly
Chemical Hygiene Officer
THE LABORATORY STANDARD
The Occupational Safety and Health Administration's (OSHA) regulation for "Occupational Exposures to Hazardous Chemicals in Laboratories", 29CFR 1910.1450 requires that all facilities engaged in the laboratory use of hazardous chemicals develop and implement a written "Chemical Hygiene Plan" which sets forth procedures, equipment, personal protective equipment, work practices, and policies that when implemented and used properly will protect employees from the health hazards presented by hazardous chemicals used in their workplace.
The following Information constitutes the basis for the written Chemical Hygiene Plan for all Clemson University laboratory employees who work in areas where hazardous chemicals are used. Laboratory supervisors must complete all segments where indicated for personnel, laboratory-specific information, policies, and procedures. It is impossible to design a set of rules that will cover all possible hazards and occurrences. The most important rule is that everyone involved in laboratory operations, from the highest administrative level to the individual worker, must be safety minded. Safety awareness can become part of everyone's habits only if the issue of safety is discussed repeatedly and only if senior and responsible faculty and staff evince a sincere and continuing interest in providing a safe and healthy work environment.
Chemical hygiene is subject to development, advancement and change. Accordingly, this guide will be revised as necessary.
Employees who work with hazardous chemicals in a laboratory must be informed of the location and availability of this plan.
The Occupational Safety and Health Administration (OSHA) requires that laboratory employees be made aware of
the Chemical Hygiene Plan at their place of employment (29 CFR 1910.1450).
After reading the "Clemson University Chemical Hygiene Plan and Hazardous Materials Safety Manual," please complete and return a copy of this form to your supervisor or to your departmental safety coordinator/contact. By signing below you acknowledge that you are aware of the policies and procedures set forth in the University Chemical Hygiene Plan.
Your supervisor will provide additional information and specific training as appropriate.
Please type or print legibly.
Name: _______________________________
Work Phone:__________________________
Staff or Student ID number: ______________________________________________
Department: __________________________________________________________
Job Title (if employee): __________________________________________
Building: ______________________ Room: _______________________________
(if student): ___________________________________
Supervisor, instructor, or P.I. for your area: _____________________________
Signature: _____________________________________ Date:________________
Completed Chemical Hygiene Plan Awareness Certifications are to be filed in a central administrative location within the staff member’s department. A list of names and ID numbers with signatures may be attached to or inserted after this page rather than filing individual names for employees/students under the supervision of one faculty member. These and all safety training records should be organized in a way that allows original records to be retrieved quickly and efficiently on request by an OSHA inspector or a EHS staff member, and to be retrieved for a single staff member or for an entire work group (identified by supervisor).
CHEMICAL HYGIENE PLAN
Section
I. Personnel Designations
A. Specific Personnel Responsibilities
B. Chemical Hygiene Officer Responsibilities
II. Approval of Laboratory Procedures
A. Chemical Hazards Subcommittee
B. Biohazards Subcommittee
C. Recombinant DNA Subcommitee
III. Standard Operating Procedures
A. General Requirements
1. Safe Work Practices With Chemicals
2. Safe Work Practices With Laboratory Equipment
3. The Laboratory Facility
4. Chemical Procurement, Distribution, and Storage
5. Housekeeping, Maintenance, and Inspections
6. Protective Apparel and Equipment
7. Records
8. Signs and Labels
9. Spills and Other Laboratory Incidents
10. Waste Disposal Program
11. Project Review
12. Synthesized Substances
B. Laboratory Specific Operating Procedures
IV. Ventilation Equipment Performance
A. General Requirements
1. Chemical Fume Hoods
2. Types of Fume Hoods
3. Special Purpose Fume Hoods
4. Other Ventilation Devices
5. Special Ventilation Areas
B. Specific Criteria
V. Standards for Handling Compressed Gas Cylinders
A. Introduction
B. General Standards
C. Restricted Products
D. Flammable Gases
E. Acceptance of Cylinders From Vendors
F. Handling and Storage of Cylinders
G. Pressure Regulators and Needle Valves
H. Leak Testing
I. Empty Cylinders
J. Hydrostatic Testing
K. Lecture Bottles
L. Acetylene
M. Cryogens
N. Compressed Air
VI. Reduction of Employee Exposure
A. General Requirements
1. Employee Exposure Determination
2. Chemical Spill or Leak
3. Odor Detection
4. Signs and Symptoms of Overexposure
B. Specific Criteria
VII. Medical Consultations and Examinations
A. General Requirements
B. Medical Programs
C. Specific Medical Requirements
VIII. Particularly Hazardous Substances
A. Routes of Exposure
B. Handling Procedures for Various Substances
C. Laboratory Specific Operating Procedures
IX. Employee Information and Training
A. General Requirements
1. Information
2. Training
B. Specific Training Required for Employees
X. Acronyms, Definitions, and Common Terms Used in Material Safety Data Sheets
XI. References
XII. EHS Personnel Information
APPENDICES
A. Obtaining a Material Safety Data Sheet
B. Hazardous Chemical Inventory Form
C. Guidelines for The Storage of Laboratory Chemicals
D. Procedures for Handling Chemical Spills
E. Signs and Labels
F. Shock Sensitive and Highly Reactive Chemicals
G. Hydrofluoric Acid
H. Personal Protective Equipment
I. Laboratory Inspection Checklist
J. Training and Information Resources
K. Creating Standard Operating Procedures
L. Use of Perchloric Acid
M. Procedure for Cleaning Lab Coats
N. Emergency Drench Equipment
Personnel Designations
The University Chemical Hygiene Program is overseen by the University’s Chemical Hygiene Officer (CHO) who reports to the Director of Environmental Health and Safety (EHS).
A. Personnel Responsibilities
1. Clemson University President: Ultimately responsible for chemical hygiene within the institution and must, with other administrators, provide continuing support for institutional chemical hygiene and other safety related compliance.
2. Department Heads or their designees responsibilities include:
a. Working with the Chemical Hygiene Officer, administrators, and other employees to develop and implement appropriate chemical hygiene policies and practices
b. Monitoring procurement, use, and disposal (including recycling) of chemicals used in the lab
c. Seeing that appropriate audits are maintained
d. Helping project directors develop precautions and provide adequate facilities
e. Knowing the current legal requirements for regulated substances
f. Seeking ways to improve the chemical hygiene program
g. Maintain discipline and enforce rules
3. Principal Investigator or Laboratory Supervisor responsibilities include:
a. Ensuring that workers know and follow the chemical hygiene rules.
b. Providing regular, formal chemical hygiene and housekeeping inspections including routine inspections of emergency equipment.
c. Knowing the current legal requirements concerning regulated substances.
d. Determining the required levels of protective apparel and equipment; ensuring that protective equipment is available and in working order; ensuring that appropriate training has been provided; and ensuring that employees are using personal protective equipment when required.
e. Require that visitors to the laboratory follow the same rules as other laboratory workers and are escorted and supervised at all times.
f. Ensure that faculty, students, and staff have access to, understand, and are able to comply with the information on the appropriate MSDSs.
g. Carefully review all procedures for possible health, safety, and environmental problems before the work is begun.
h. Ensure that facilities, equipment, and training for use of any material being ordered are adequate before the material is ordered.
i. Observing the rules and recommendations outlined in the Chemical Hygiene Plan.
j. Wearing protective equipment where required.
k. Maintain discipline and enforce rules.
4. Laboratory Workers are responsible for:
a. Planning and conducting each operation in accordance with the institutional chemical hygiene procedures.
b. Following prescribed safety practices and University policies and procedures.
c. Developing good personal chemical hygiene habits.
d. Know the location of and how to use the emergency equipment in your area, as well as how to obtain additional help in an emergency, and be familiar with emergency procedures.
B. Chemical Hygiene Officer Responsibilities
1. Work with administrators and other employees to develop and implement appropriate chemical hygiene policies and practices.
2. Maintain appropriate audits.
3. Help departments develop Standard Operating Procedures for the hazardous operations.
4. Seek ways of improving the Chemical Hygiene Plan.
5. Update and revise the Chemical Hygiene Plan as necessary (review at least annually).
6. Perform random safety reviews.
7. Develop and maintain a Chemical Hygiene training program.
8. Review the Chemical Hygiene Program and training programs at least yearly, and make necessary changes.
9. Know the current legal requirements concerning regulated substances.
Institutional Biosafety Committee (IBC)
Overview:
Clemson University aims to provide a safe and healthy work environment for faculty, staff, students and visitors. The intent is to minimize, to the extent practicable, all recognizable hazards and to comply with all federal and State laws and regulations.
The Office of Research Compliance (ORC) provides support and training for faculty, staff, and students in regulatory requirements for research and teaching activities involving vertebrate animals, research involving the use of human subjects, and research involving the use of recombinant DNA and hazardous agents. The ORC is responsible for the development and implementation of University policies and for coordinating institutional compliance with federal and state law-regulations. The ORC supports the university community in promoting the responsible conduct of research. Information about the ORC can be accessed at: http://www.clemson.edu/research/orcSite/indexComply.htm
The Institutional Biosafety Committee (IBC) is responsible for reviewing all research that involves the use of recombinant DNA, biological hazards (including human blood, tissue, infectious agents, cell lines and select agents) and chemical hazards (that are highly toxic, mutagenic, teratogenic, carcinogenic, explosive or on the Schedule I and II drugs) and ensuring that the proposed activities comply with the federal regulations governing them. The role of the committee is to ensure the safety of personnel working with these materials and that laboratory practices conform to federal and state regulations. Recombinant DNA being considered in this context is defined as work with those molecules which are constructed outside living cells by joining natural or synthetic DNA segments to DNA molecules that can replicate in a living cell or which result from the replication of those described above.
All research activities as described above, regardless of source of funding, must be reviewed by the IBC. The IBC has the responsibility and authority to review, approve, disapprove, or require changes in research activities. The IBC holds meetings as needed to review protocols. This is usually on a monthly basis. Clemson University’s IBC is registered with the National Institutes of Health’s Office of Biotechnology Activities (OBA). The IBC works closely with Clemson University’s Department of Environmental Health and Safety. Research activities may also involve the use of animals or humans. In these instances, research applications also need to be reviewed and approved by respective research compliance committees.
The basis of compliance for the IBC is determined by the “NIH-Guidelines for Research Involving Recombinant DNA Molecules” (April 2002). The NIH Guidelines state that the Institutional Biosafety Committee’s (IBC) responsibilities need not be restricted to recombinant DNA research. Clemson University, at the present time, has elected to expand the scope of the IBC to include the review of hazardous biological and hazardous chemical agents.
Information about the IBC, its regulations and policies, and steps in getting started can be accessed at: http://www.clemson.edu/research/orcSite/indexComply.htm
Current IBC forms can be obtained at: http://www.clemson.edu/research/orcSite/orcIBC_Forms.htm
RECOMBINANT DNA:
The Clemson University IBC reviews and oversees projects that deal with recombinant DNA technologies. Clemson University’s IBC is made up of faculty, staff, and community members, for the review of protocols and compliance in recombinant DNA matters. While the most scrutinized protocols are those dealing with human gene therapy or the environmental release of genetically engineered organisms, all protocols including those using only laboratory contained experiments are closely examined. CU has a policy of requiring that all investigators file a protocol when using recombinant DNA molecules or
organisms, although certain types of experiments will qualify as "Exempt". The determination of “exempt from review of the Full IBC Committee” is made by the IBC and not the investigator. This process guarantees our compliance with Federal regulations, and allows us to assure the public that we are safeguarding the public interest.
If you work with recombinant DNA, (see Section I-B of the NIH Guidelines: Definition of Recombinant DNA Molecules, NIH-Guidelines for Research Involving Recombinant DNA Molecules” (April 2002), a component of the protocol form will require you to identify the section(s) and appendices of the NIH Guidelines appropriate for your experiments. A copy of the Guidelines for Research Involving Recombinant DNA Molecules is available on the Internet at http://www.nih.gov/od/oba/ or on the IBC website.
If you plan at any time to introduce genetically engineered organisms into the environment, additional information must be filed. For this component, you will need to complete Steps 1-4 in Part D of the protocol. You also will need to reference the USDA publication entitled Guidelines for Research Involving Planned Introduction into the Environment of Genetically Modified Organisms (December 3-4, 1991 or the most current version. This guide is located at http://www.aphis.usda.gov/brs/pdf/abrac%201991.pdf
Non-exempt recombinant DNA work will require Full Committee Review.
The following is a description of biological and hazardous chemicals that are reviewed by the IBC.
Biological Hazards:
A biohazard is a potentially dangerous infectious or toxic agent or material (tissue, blood, etc.) that
is suspected to contain an infectious agent or whose hazard status is unknown.
For Clemson University’s purpose, a biohazard is any BSL2 agent or above, or
human or animal blood, tissue, or waste specimen has the potential to harbor
infections agents or whose biohazard status is unknown. Human or non-human
primate derived cell lines or similar are also considered biohazards (per OSHA
definition). Infectious organisms include all agents (including prions)
capable of causing disease in healthy humans or animals, whether these occur
commonly in the environment or not.
The Center for Disease Control-NIH Biosafety in Microbiological and Biomedical Laboratories 5th edition manual http://www.cdc.gov/od/ohs/biosfty/bmbl5/bmbl5toc.htm should be used in completing the Biohazards Protocol section. Before any lab work with biohazards can be initiated, it is a requirement that all “hands on” personnel be enrolled in the Medical Surveillance Program (MSP), take Bloodborne Pathogen Training in the OSHA Standard on an annual basis and be offered appropriate inoculations against any pathogen for any occupational health purposes. If inoculations are not accepted, a waiver must be signed. Regardless of the source, if using human (including human cell lines) or non-human primate tissue or body fluid(s), a protocol will be required.
CHEMICAL HAZARDS:
any chemical listed as highly toxic, carcinogenic (confirmed or suspected), mutagenic, teratogenic or explosive on its MSDS must be covered by an approved protocol. If unqualified undergraduates are involved in the research then any chemical listed as toxic, highly toxic, carcinogenic (confirmed or suspected), teratogenic or explosive on its MSDS must be covered and the protocol. Unqualified undergraduates are those that lack at least a year of college level chemistry and biological science (e.g. general biology, microbiology, inorganic, organic biochemistry) or are under the age of 18.
Highly toxic agent is defined as:
1) A chemical that has a median lethal dose (LD50) of 50 milligrams or less per kilogram of body weight when administered orally to albino rats weighing between 200 and 300 grams each.
2) A chemical that has a median lethal dose (LD50) of 200 milligrams or less per kilogram of body weight when administered by continuous contact for 24 hours (or less if death occurs within 24 hours) with the bare skin of albino rabbits weighing between two and three kilograms each.
3) A chemical that has a median lethal concentration (LC50) in air of 200 parts per million by volume or
less of gas or vapor, or 2 milligrams per liter or less of mist, fume, or dust, when administered by continuous inhalation for one hour (or less if death occurs within one hour) to albino rats weighing between 200 and 300 grams each.
Toxic agent is defined as:
1) A chemical that has a median lethal dose (LD50) of more than 50 milligrams per kilogram but not more than 500 milligrams per kilogram of body weight when administered orally to albino rats weighing between 200 and 300 grams each.
2) A chemical that has a median lethal dose (LD50) of more than 200 milligrams per kilogram but not more than 1,000 milligrams per kilogram of body weight when administered by continuous contact for 24 hours (or less if death occurs within 24 hours) with the bare skin of albino rabbits weighing between two and three kilograms each.
3) A chemical that has a median lethal concentration (LC50) in air of more than 200 parts per million but not more than 2,000 parts per million by volume of gas or vapor, or more than two milligrams per liter but not more than 20 milligrams per liter of mist, fume, or dust, when administered by continuous inhalation for one hour (or less if death occurs within one hour) to albino rats weighing between 200 and 300 grams each.
Explosive agent is defined as the use of explosive material for their explosive property. The PI must contact EHS (Naomi Kelly at 864-656-1806).
EHS also requires that individuals working with chemicals at Clemson University take Chemical Hygiene training (http://ehs.clemson.edu/taining/CHP/index.html) and Hazardous Waste Management Training (http://ehs.clemson.edu/training/hazwaste/index.html).
RECOMBINANT DNA:
By definition (Federal Register 51 (88) page 16959 I-D-2), the CU IBC reviews and oversees projects that deal with recombinant DNA (rDNA) technologies. Clemson University must have such a committee made up of faculty, staff, and community members, for review of protocols and compliance in rDNA matters. While the most scrutinized protocols are those dealing with the environmental release of genetically engineered organisms, all protocols including those using only laboratory contained experiments are closely examined. CU has a policy of requesting that all investigators file a protocol when using rDNA molecules or organisms, although certain types of experiments will qualify as "Exempt". This process guarantees our compliance with Federal regulations and allows us to assure the public that we are safeguarding the public interest.
If you work with recombinant DNA, (see Section I-B of the NIH Guidelines: Definition of Recombinant DNA Molecules), a component of the protocol form will require you to identify the section(s) and appendices of the NIH Guidelines appropriate for your experiments. A copy of the Guidelines for Research Involving Recombinant DNA Molecules is available on the Internet at http://www.nih.gov/od/oba/. A hard copy is available in the Office of Research Compliance.
If you plan at any time to introduce genetically engineered organisms into the environment, additional information must be filed. For this component, you will need to complete Steps 1-4 in Part D of the protocol. You also will need to reference the USDA publication entitled Guidelines for Research Involving Planned Introduction into the Environment of Genetically Modified Organisms (December 3-4, 1991 or most current version).
Standard Operating Procedures
The following standard operating procedures must be followed by all laboratory workers where
laboratory work involves the use of hazardous chemicals.
A. General Requirements
1. Safe Work Practices With Chemicals
a. Minimize all chemical exposures: Because few laboratory chemicals are without hazards, general precautions for handling all laboratory chemicals should be adopted, along with specific guidelines for particular chemicals as needed. Skin contact with chemicals and inhalation of vapors should be avoided as a cardinal rule.
b. Avoid underestimation of risk: Even for substances of no known significant hazard, exposure should be minimized. For work with substances which present special hazards, special precautions should be taken. One should assume that any mixture will be more toxic than its most toxic component and that all substances of unknown toxicity are toxic. Refer to the Material Safety Data Sheet for specific information about a chemical or product containing hazardous chemicals. (See Appendix A, Obtaining a Material Safety Data Sheet)
c. Provide adequate ventilation: The best way to prevent exposure to airborne substances is to prevent their
escape into the working atmosphere by use of chemical hoods or biosafety cabinets other ventilation devices.
One should be familiar with the proper operation and use of a chemical hood. (See Section IV -Ventilation)
d. Institute a chemical hygiene program: A mandatory chemical hygiene program designed to minimize exposures has been prepared. Its implementation should be a regular, continuing effort, not merely a standby or short-term activity. This program should be followed by all laboratory personnel including employees, guest researchers, students, and visitors.
e. Material Safety Data Sheets: Material Safety Data Sheets must be available for all hazardous chemicals. MSDSs must be readily accessible to all employees who are working with or who might be exposed to hazardous chemicals. Those employees must be informed of the location of MSDSs; understand how to use information on the MSDSs; and must be able to comply with the information on the appropriate MSDS. (See Appendix A)
f. Observation of PELS, TLVs, or RELS: Permissible Exposure Limits (PELS) of OSHA are exposure limits set by OSHA, and must not be exceeded. Threshold Limit Values (TLVS) of the American Conference of Governmental Industrial Hygienists, or Recommended Exposure Limits (RELS) of the National Institute for Occupational Safety and Health) may also be used as guidelines in determining exposure levels. Even chemicals with high TLVs, PELs, or RELs should be used under chemical hoods whenever possible. PELs, TLVs and other exposure limits can be found on material safety data sheets.
g. Accidents and spills: (The following information applies to most chemical spills on a person. Some chemicals may have special first aid requirements. Consult the MSDS and other sources of information. For hydrofluoric acid, see Appendix G. For additional information on spills, see Appendix D).
· Eye Contact: Promptly flush eyes with water for a prolonged period (at least 15 minutes) and seek medical attention.
· Ingestion: Call 911 and report the nature of the chemical uptake. When reporting any accident or spill to the dispatcher please give the following information: your name, the location of the incident, and the nature and extent injury or symptoms. After calling 911, the Poison Control Center (1-800-922-1117) may be called for information on action that may be taken before the arrival of the EMS.
· Skin Contact: Promptly flush the affected area with copious amounts of water and seek medical attention. Remove any clothing that may have chemical contamination to prevent further exposure.
· Clean-up : Promptly clean up spills when appropriate or Call 911 for assistance from the HazMat Team; notify others in the building and evacuate. (See Appendix D).
· Employees involved in an accident or spill incident should immediately report the incident to their supervisor. If there is reason to believe that exposure has occurred during a chemical spill or release, the worker should promptly report to Redfern Health Center for medical consultation and possible evaluation based on the physician’s assessment. For injuries or exposures occurring after 4:30pm, employees should be taken to the Clemson Health Center on Highway 123 in Clemson or the emergency room at Oconee Memorial Hospital or Anderson Memorial Hospital.
h. Avoidance of "routine" Exposure
· Develop and encourage safe habits
· Avoid unnecessary exposure to chemicals by any route.
· Do not smell or taste chemicals.
· Vent any apparatus which may discharge toxic chemicals (e.g., vacuum pumps, distillation columns) into direct exhaust devices.
· Chemicals should be properly stored and used in a safe manner to prevent exposure.
· Do not allow release of toxic substances in cold rooms and warm rooms, since these have contained recirculated atmospheres.
· Use a chemical hood whenever possible when working with any hazardous chemical.
i. Choice of Chemicals: Use only those chemicals for which the quality of the available ventilation system is appropriate. Also, consideration should be given to selection of chemicals used. Where choices and chemical substitutes can be made, always choose chemicals having the lowest level of toxicity.
j. Eating, Smoking, Etc.
Because of the potential increase in the risk of infection and exposure to personnel, it is necessary to prohibit smoking, eating, drinking, and storage of food in laboratories which handle infectious or toxic materials or radioisotopes. An area or areas which provides complete physical separation from these laboratories should be established for the storage and consumption of food and beverage. These areas should be prominently posted (e.g., AREA FOR STORAGE AND CONSUMPTION OF FOOD, NO CHEMICALS). No chemical or chemical equipment should be allowed in such areas. Laboratory refrigerators, ice chests, cold rooms, and such should be properly labeled (e.g., NO FOOD OR BEVERAGE STORED IN THIS…). Laboratory doors should be posted (DO NOT EAT, DRINK, OR SMOKE IN THIS AREA).
· Do not eat, drink, chew gum, or apply cosmetics in areas where laboratory chemicals are present.
· Always wash hands before conducting these activities.
· Do not store or consume food or beverages in areas where chemicals are stored, handled, or used.
· Glassware or utensils which are also used for laboratory operations must never be used with food or beverages.
k. Equipment and Glassware: Handle and store laboratory glassware with care to avoid damage; do not use damaged glassware. Use extra care with Dewar flasks and other evacuated or pressurized glass apparatus; shield or wrap them to contain chemicals and fragments should implosion occur. Use equipment only for its designed purpose.
l. Personal Hygiene: Thoroughly wash hands immediately after working with chemicals.
m. Visitors: No children under 16 years of age are allowed into any laboratory or animal holding area except with the special permission of the Director, Environmental Health and Safety, or the Director of the Research and Education Center. No pets are allowed in any University building. Whenever visitors are allowed into a laboratory, it is the responsibility of the laboratory supervisor to ensure that they are supervised at all times, and that they follow the same rules as laboratory employees.
n. Avoid practical jokes or other behavior which might confuse, startle or distract another worker.
o. Mouth pipetting: Do not use mouth suction for pipetting or starting a siphon.
p. Syringes and Scalpel Blades
Syringes used with hazardous agents shall have needle-locking or equivalent tips to assure that the needles cannot separate during use. All needles, syringes, scalpels, and other sharps should be placed into puncture-proof sharps disposal containers and disposed of as biohazardous waste through the Department of Environmental Health and Safety.
Contact the Hazardous Waste Manager at 656-1770 to obtain sharps containers.
Do not recap needles after use.
q. Housekeeping: Good housekeeping is essential in laboratories. Keep the work area clean and uncluttered. Properly label and store chemicals and equipment; clean up the work area on completion of an operation or at the end of each day.
r. Planning: Seek information and advice about hazards, plan appropriate protective procedures, and plan positioning of equipment before beginning any new operation.
s. Unattended operations: It is recommended to leave no process/experiment unattended. If experiments must run while a researcher is not present, a sign containing information about the experiment and the name of the contact person for emergencies should be posted on the laboratory door. Lights should be left on and containment for toxic substances should be provided. In the event of a failure of a utility service such as cooling water or electricity to an unattended operation, provisions should be made in advance if a utility failure could result in a hazardous condition. Equipment such as power stirrers, hot plates, heating mantles, and water condensers should be equipped with fail-safe provisions such as flow monitors that will shut down equipment in case of water supply failure or fluctuation in water pressure, temperature monitors interlocked into the system, or fail-safe hose connectors.
Remember that at night, emergency personnel rely on accurate written instructions and information available at the site.
t. Planning: Seek information and advice about hazards, plan appropriate protective procedures, and plan positioning of equipment before beginning any new operation.
u. Vigilance: Be alert of unsafe conditions and see that they are corrected when detected.
x. Working alone: Avoid working alone in a building; do not work alone in a laboratory if the procedures being conducted are hazardous.
y. Transfer of chemicals into other containers: When transferring any hazardous substance into another container, you must ensure that the new container is compatible with the material being transferred before making the transfer. Never transfer any hazardous chemical into a container which was originally used to store food or food products.
z. Personal apparel
· Confine long hair and loose clothing.
· Suitable clothing shall be worn in the laboratory; shorts, short skirts and sandals/open shoes are not allowed.
· Clothing may absorb liquid spills that would otherwise come in contact with your skin. Long sleeves and long pants should be worn. Shorts, short skirts, etc. are not allowed in laboratories.
· Synthetic fabrics may increase the severity of injury in case of fire. Cotton is less prone to static electricity buildup than nylon or other synthetics.
· Wear substantial leather shoes in the laboratory to protect against chemical splashes or broken glass. Sandals, cloth sport shoes, perforated shoes, open-toed shoes, or high-heeled shoes may not be worn in laboratories.
2. Safe Practices with laboratory equipment
a. Equipment maintenance: Good equipment maintenance is important for safe, efficient operations. Equipment should be inspected and maintained regularly. Servicing schedules will depend on both the possibilities and the consequences of failure. Maintenance plans should include a procedure to ensure that a device that is out of service cannot be restarted.
b. Guarding: All mechanical equipment should be adequately furnished with guards that prevent access to electrical connections or moving parts (such as the belts and pulleys of a vacuum pump). Each laboratory worker should inspect equipment before using it to ensure that the guards are in place and functioning.
c. Shielding: Safety shielding should be used for any operation having the potential for explosion such as (a) whenever a reaction is attempted for the first time (small quantities of reactants should be used to minimize hazards); (b) whenever a familiar reaction is carried out on a larger than usual scale; (c) whenever operations are carried out under non-ambient conditions. Shields must be placed so that all personnel in the area are protected from the hazard.
d. Glassware: Accidents involving glassware are a leading cause of laboratory injuries.
· Borosilicate glassware is recommended for all laboratory glassware except for special experiments that use UV or other light sources.
· Careful handling and storage procedures should be used to avoid damaging glassware. Damaged items should be discarded or repaired.
· Adequate hand protection should be used when inserting glass tubing into rubber stoppers or corks or when placing rubber tubing on glass hose connections. Tubing should be fire polished or rounded and lubricated, and hands should be held close together to limit movement of glass should fracture occur. The use of plastic or metal connectors should be considered.
· Glass-blowing operations should not be attempted unless proper annealing facilities are available.
· Vacuum jacketed glass apparatus should be handled with extreme care to prevent implosions. Equipment such as Dewar flasks should be taped or shielded. Only glassware designed for vacuum work should be used for that purpose.
· Hand protection should be used when picking up broken glass.
· Proper instruction should be provided in the use of glass equipment designed for specialized tasks, which can represent unusual risks for the first-time user. (For example, separatory funnels containing volatile solvents can develop considerable pressure during use.)
e. Cold Traps and Cryogenic Hazards: The primary hazard of cryogenic materials is their extreme coldness. These, and surfaces they cool, can cause severe burns if allowed to contact the skin. Gloves and a face shield should be used when preparing or using some cold baths. Neither liquid nitrogen nor liquid air should be used to cool a flammable mixture in the presence of air because oxygen can condense from the air, which can cause an explosion hazard. Cryogenic or loose, dry leather gloves must be used when handling dry ice, which should be added slowly to the liquid portion of the cooling bath to avoid foaming over. Workers should avoid lowering their head into a dry ice chest (carbon dioxide is heavier than air, and suffocation can result).
f. Systems Under Pressure: Reactions should never be carried out in, nor heat applied to, an apparatus that is a closed system unless it is designed and tested to withstand pressure. Pressurized apparatus should have an appropriate relief device. If the reaction cannot be opened directly into the air, an inert gas purge and bubbler system should be used to avoid pressure buildup. Appropriate shielding must be provided whenever chemicals are heated or reactions are carried out in systems under pressure.
g. Extractions and Distillations
Extractions:
Extractions can present a hazard because of the potential buildup of pressure from a volatile solvent and an immiscible aqueous phase. Glass separatory funnels used in laboratory operations are particularly susceptible to problems because their stoppers or stopcocks can be forced out, resulting in a spill of the contained liquid. It is even possible for pressure to burst the vessel.
To use a separatory funnel correctly, do not attempt to extract a solution until it is cooler than the boiling point of the extractant. When a volatile solvent is used, the unstoppered separatory funnel should first be swirled to allow some solvent to vaporize and expel some air. Close the funnel and invert it with the stopper held in place and immediately open the stopcock to release more air plus vapor. Do this with the hand extended around the barrel to keep the stopcock plug securely seated.
Point the barrel of the separatory funnel away from yourself and others and vent it to the hood. Do not vent the funnel near a flame or other ignition source. Close the stopcock, shake with a swirl, and immediately open the stopcock with the funnel in the inverted position to vent the vapors again. If it is necessary to use a separatory funnel larger than one liter for an extraction with a volatile solvent, the force on the stopper may be too great, causing the stopper to be expelled. Consider performing the extraction in several smaller batches.
Distillations:
Potential dangers arise from pressure buildup, commonly used flammable materials, and the use of heat to vaporize the chemicals involved. Careful design and construction of the distillations system is required to accomplish effective separation and avoid leaks that can lead to fires or contamination of the work area.
It is necessary to ensure smooth boiling during the separation process and avoid bumping, which can blow apart the distillation apparatus. Stirring the distillation mixture is the best method to avoid bumping. Boiling stones are only effective for distillations at atmospheric pressure. Use fresh boiling stones when a liquid is boiled without stirring. Do not add boiling stones or any other material to a liquid that is near its boiling point, because this may cause it to boil over spontaneously.
An electric mantle heater, a ceramic cavity heater, steam coils, or a nonflammable liquid bath are the best to provide even heating. Silicone oil or another suitable high-boiling-temperature oil can be used on a hot plate. Hot water or steam may also be used in some cases. An extra thermometer inserted at the center bottom of the distilling flask will warn of dangerously high temperatures that could indicate exothermic decomposition. Do not distill or evaporate organic compounds to dryness unless they are known to be free of peroxides.
Because superheating and bumping occur frequently during distillation using reduced pressure, it is important that the distillation assembly is secure and the heat distributed more evenly than is possible with a flame. Evacuate the assembly gradually to minimize the possibility of bumping. Stirring, or using an air or nitrogen bleed tube, provides good vaporization without overheating and decomposition.
Put a standing shield in place for protection in the event of implosion. After finishing a reduced-pressure distillation, cool the system, then slowly bleed in air so as not to induce an explosion in a hot system. Pure nitrogen is preferred to air and can be used even before cooling the system.
In a steam distillation, minimize the accumulation of condensate in the distillation flask. The heat of steam condensation is very high, and overfilling the flask is less likely if condensation from the entering steam line is trapped and the flask heated or insulated to prevent excessive condensation.
h. Electrical Equipment: Electrical currents of very low amperage and voltage may result in fatal shock under certain circumstances. Voltages as low as 24 volts AC can be dangerous and present a lethal threat. Low-voltage DC currents do not normally present a hazard to human life, although severe burns are possible. The duration of contact with a live circuit affects the degree of damage, especially with regard to burns.
· All electrical switches shall be labeled, including circuit breakers in the service panels, and all laboratory personnel shall know where these controls are and how to shut off circuits or equipment in case of fire or other accident. Any electrical equipment that is not operating properly or seems to be overheating shall be turned off immediately and inspected by a qualified person.
· Electrical equipment should be inspected periodically to confirm that the cords and plugs are safe condition. Circuit diagrams, operating instructions, descriptions of hazards, and safety devices are usually provided by the manufacturer and should be kept on file for reference.
· Only three-wire grounded, double insulated, or isolated wiring and equipment shall be used in 110V-115V AC applications. All wiring and equipment shall comply with the National Electrical Code. In specifically designated laboratories, cold rooms, or storage rooms or other locations where concentrations of flammable vapor-air mixtures are likely to occur, certified explosion-proof wiring and equipment, including light fixtures, switches, and refrigerators shall be used. If you have any questions with regard to the code, contact the Office of Environmental Health and Safety.
· Series-wound motors with carbon brushes, typically found in household appliances such as blenders and mixers, are not spark-free and shall not be used in laboratories where flammable vapors accumulate. Equipment manufactured for use in laboratories generally contains induction motors.
· Electrical extension cords should be avoided where practical by installing additional electrical outlets. When they are used, the wire gauge shall be equal to or larger than the size of the cord being plugged into them. Electrical cords on equipment shall be discarded or repaired if frayed or damaged. Cords should be kept as short as practical to avoid tripping hazards and tangles.
· Place electrical equipment so as to minimize the possibility that water or chemicals could spill on it or that water could condense and enter the motor or controls. In particular, place such equipment away from safety showers. In cold rooms, minimize condensation by mounting electrical equipment on walls or vertical panels.
· Electrical equipment shall be de-energized and tagged or locked out according to OSHA requirements before repairs are made. If adjustments or other contacts are to be made with energized electrical equipment, a second person shall be present. Be sure you are not on a damp surface or touching a potential grounding surface. Use insulated tools, keep your hands dry, and wear safety glasses to prevent injury from sparks.
· If a worker receives an electrical shock and is in contact with the energized device, turn off the current if possible; or use nonconducting gloves or a nonconducting device to pull or push the victim free from the current source. Help victims only if you are certain that you will not endanger your own safety.
i. Static Electricity
Static electricity in association with the use of flammable liquids presents a significant hazard in the laboratory. Static electricity is found wherever equipment is in operation, materials are processed, liquids are being poured, or personnel are moving about. Some common potential sources of electrostatic discharges are ungrounded metal tanks and containers; metal-based clamps, nipples, or wire used with nonconducting hoses; high-pressure gas cylinders upon discharge; and clothing or containers made of plastic or synthetic materials.
· High voltages can be attained in a relatively short time span.
· Hazard is greatest during wintertime when the air is dry, but often air conditioning can remove enough moisture for a hazard to exist during summer months.
Many methods can be used to ground static electricity, but because of existing conditions in some areas the use of these grounding devices may be impossible to implement. Thus, personnel become the source of static charge. If personnel are engaged in work that could be hazardous because of accidental discharge of static electricity and cannot use grounding devices on their person, the simplest way to assure grounding is to make a contact with a water pipe. The static charge will transfer to ground via the pipe.
Some commercially available devices for eliminating static electricity follow:
· Humidifiers
· Grounding straps : conductive strips or straps connected to machine belts, pulleys, and containers connected to the ground.
· Conductive materials : conductive floor mats, bags, hose containers and container covers connected to the ground.
· Personnel protection : shoe straps, wrist straps, aprons, gloves, and clothes, conductive items used in conjunction with other devices to assure grounding of personnel.
i. Centrifuges
If a tabletop centrifuge is used, make certain that it is securely anchored in a location where its vibration will not cause bottles or equipment to fall. Centrifuge rotors shall be balanced each time they are used. Securely anchor and shield each unit against flying rotors. Regularly clean rotors and buckets with noncorrosive cleaning solutions.
Always close the centrifuge lid during operation, and do not leave the centrifuge until full operating speed is attained and the machine appears to be running safety without vibration. Stop the centrifuge immediately and check the load balances if vibration occurs. Check swing-out buckets for clearance and support.
j. Vacuum Pumps
If vacuum pumps are used with volatile substances, the input line to the pump shall be fitted with a cold trap to minimize the amount of volatiles that enter the pump and dissolve in the pump oil. The exhaust from evacuation of volatile, toxic, or corrosive materials shall be vented to an air exhaust system.
k. Drying Ovens and Furnaces
Electrically heated ovens are commonly used in the laboratory to remove water or other solvents from chemical samples and to dry laboratory glassware before its use. With the exception of vacuum drying ovens, these ovens rarely have any provision for preventing the discharge of the substances volatilized in them into the laboratory atmosphere. Thus, it should be assumed that these substances will escape into the laboratory atmosphere and could also be present in concentrations sufficient to form explosive mixtures with the air inside the oven.
Ovens should not be used to dry any chemical sample that has even moderate volatility and might pose a hazard because of acute or chronic toxicity unless special precautions have been taken to ensure continuous venting of the atmosphere inside the oven. Thus, most organic compounds should not be dried in a conventional laboratory oven.
Glassware that has been rinsed with an organic solvent should not be dried in conventional ovens. If such rinsing is necessary, the item should be rinsed again with distilled water before being placed in the oven.
Because of the possible formation of explosive mixtures by volatile substances and the air inside an oven, laboratory ovens should be constructed so that their heating elements (which may become extremely hot and their temperature controls (which may produce sparks) are physically separated from their interior atmospheres. Small household ovens and other similar devices do not meet this requirement and, consequently, should not be used in laboratories. Existing ovens that do not meet these requirements should have a sign attached to the oven door to warn workers that flammable materials should not be placed in that oven.
Mercury thermometers should not be used in drying ovens.
l. Refrigerators
The potential hazards posed by laboratory refrigerators are in many ways similar to those of laboratory drying ovens. Because there is almost never a satisfactory arrangement for continuously venting the interior atmosphere of a refrigerator, any vapors escaping from vessels placed in one will accumulate. Thus, the atmosphere in a refrigerator could contain an explosive mixture of air and the vapor of a flammable substance of a dangerously high concentration of the vapor of a toxic substance or both. (The problem of toxicity is aggravated by the practice of laboratory worker who place their faces inside the refrigerator while searching for a particular sample, thus ensuring the inhalation of some of the atmosphere from the refrigerator interior). The placement of highly toxic substances in a laboratory refrigerator should be avoided.
There should be no potential sources of electrical sparks on the inside of a laboratory refrigerator. Refrigerators used for the storage of flammable liquids should be a refrigerator designed by the manufacturer for the storage of flammables. All refrigerators used in laboratories should preferably be “flammable” storage or, if necessary, “explosion-proof”. If, however, there are existing laboratory refrigerators which are used to store materials which do not fall into these categories, a prominent sign should be affixed to the refrigerator (e.g., NO FLAMMABLES TO BE STORED IN THIS REFRIGERATOR).
Laboratory refrigerators should be placed against fire-resistant walls, have heavy-duty electrical cords, and preferably should be protected by their own circuit breaker.
Uncapped containers of chemicals should never be placed in a refrigerator. Containers of chemicals should be capped so as to achieve a seal that is both vapor tight and unlikely to permit a spill if the container is tipped over. Caps constructed from aluminum foil, corks, corks wrapped with aluminum foil, glass stoppers, or parafilm do not meet all of these criteria. The most satisfactory temporary seals are normally achieved by using containers that have screw-caps lined with either a conical polyethylene insert or a Teflon insert. The best containers for samples that are to be stored for longer periods of time are sealed, nitrogen-filled glass ampoules.
m. Heating Devices
Perhaps the most common electrical equipment found in a laboratory are the devices used to supply the heat needed to effect a reaction or a separation. The use of steam-heated devices rather than electrically heated devices is generally preferred whenever temperatures of 100C or less are required; these devices do not present shock or spark hazards. Electrically heated devices include hot plates, heating mantles and tapes, air baths, hot-tube furnaces, and hot-air guns. They are inherently much safer than burners as laboratory heat sources, however, such devices can still pose both electrical and fire hazards if used improperly.
· The actual heating element in any laboratory heating device should be enclosed in a glass, ceramic, or insulated metal case such that it is not possible for the laboratory worker (or some metallic conductor) to accidentally touch the wire carrying the electric current. This practice minimizes the hazards of electrical shock and of accidentally producing an electrical spark near a flammable liquid or vapor. This type of construction also diminishes the possibility that a flammable liquid or vapor will come in contact with the hot wire (whose temperature is frequently higher than the ignition temperature of many common solvents). If any heating device becomes so worn or damaged that its heating element is exposed, the device should either be discarded or repaired to correct the damage before it is again used in the laboratory.
· The temperature of many laboratory heating devices (e.g., heating mantels, air baths, and oil baths) is controlled by use of a variable autotransformer that supplies some fraction of the total line voltage (typically 110V) to the heating element of the device. If a variable transformer is improperly wired, the switch on it may or may not disconnect both wires of the output from the 110V line when in the off position. If a grounded three-prong plug is not used, each output line may be at a relatively high voltage (e.g., 110 and 110V) with respect to an electrical ground. Because of these possibilities, whenever a variable transformer whose wiring is not definitely known to be acceptable is used, it is best to assume that either of the output lines could be at a potential of 110V and capable of delivering a lethal electric shock.
· The cases of all variable autotransformers have numerous openings to allow for ventilation and some sparking may occur whenever the voltage adjustment knob is turned; laboratory workers should be careful to locate these devices where water and other chemicals cannot be spilled on them and where their movable contacts will not be exposed to flammable liquids or vapors. Specifically, variable autotransformers should be mounted on walls or vertical panels and outside of hoods; they should not be placed on laboratory bench tops, especially those inside of hoods.
· Whenever an electrical heating device is to be left unattended for a significant period of time, it is advisable that it be equipped with a temperature-sensing device that will turn off the electric power if the temperature of the heating device exceeds some preset limit. Similar control devices are available that will turn off the electric power if the flow of cooling water through a condenser is unexpectedly stopped. Such fail-safe devices, which can either be purchased or constructed by a qualified technician, prevent more serious problems (fires or explosions) that may arise if the temperature of an unattended reaction should increase significantly either because of a change in line voltage or because of accidental loss of reaction solvent. These devices are also valuable accessories for use with stills employed to purify reaction solvents because such stills are often left unattended for significant periods of time.
n. Assembling Apparatus
Operations that may generate airborne contaminants or that use flammable liquids or toxic, reactive, or odoriferous materials shall be conducted in a chemical fume hood or other appropriate containment enclosure. Whenever hazardous gases or fumes are likely to evolve, an appropriate trap, condenser, or scrubber shall be used to minimize release of material to the environment.
Apparatus should be set up well back from the edge of the work area. When assembled in a hood, apparatus should not obstruct the area. To avoid overflow, choose apparatus with at least 20 percent more capacity than would normally accommodate the volume of chemical planned for the operation. All parts of the apparatus shall be firmly balanced and supported. Tubing shall be fastened with wire or appropriate clamps.
Stirrer motors and vessels shall be positioned and secured to ensure proper alignment. Magnetic stirring is preferable, and nonsparking motors or air motors shall be used in any laboratory that might contain flammable vapors.
Funnels and other apparatus with stopcocks shall be firmly supported and oriented so that gravity will not loosen the stopcock plug. Use a retainer on the stopcock plug, and lubricate glass stopcocks. Do not lubricate Teflon stopcocks.
Include a vent in apparatus for chemicals that are to be heated, and place boiling stones in unstirred vessels. If a burner is to be used, distribute the heat with a ceramic-centered wire gauze. Insert a thermometer in heated liquids if dangerous exothermic decomposition is possible. This will provide a warning and may allow time to remove the heat and apply external cooling.
A pan under a reaction vessel or container will confine spilled liquids in the event of glass breakage.
If a hot plate is used, be sure that its temperature is less than the autoignition temperature of the chemicals likely to be released and that the temperature control device does not spark. Whenever possible, use controlled electrical heaters or steam in place of gas or alcohol burners.
3. The Laboratory Facility
a. Design: The laboratory facility must have:
1. An appropriate general ventilation system with air intakes and exhausts located so as to avoid re-entrainment of contaminated air.
2. Adequate, well-ventilated stockrooms/storerooms; and/or storage cabinets appropriate for chemicals being stored.
3. Laboratory chemical and biosafety hoods as required for work being done.
4. Other safety equipment including eyewash stations and emergency showers as required.
5. Arrangements for proper disposal of regulated waste. (consult the University Hazardous Waste Management Manual or call EHS at 656-1770)
b. Maintenance: Chemical hygiene-related equipment (fume hoods, chemical spill kits, storage cabinets, etc.) should undergo continuing appraisal by laboratory supervisors and be modified or replaced if inadequate.
c. Usage. The work conducted and its scale must be appropriate to the physical facilities available and, especially, to the quality of ventilation.
4. Chemical Procurement, Distribution, and Storage
a. Procurement
1. Avoid the purchase of unnecessary volumes of chemicals
2. Before a substance is received, information on proper handling, storage, and disposal should be known to those who will be involved.
3. No container should be accepted without an adequate identifying label.
4. All substances should be received in a central location.
5. If a Material Safety Data Sheet has been sent with the package, it should be distributed to the user. No hazardous chemical should be used unless the material safety data sheet is available to the user.
6. If a material safety data sheet is needed, request one from the manufacturer or call the Office of Environmental Health and Safety at 656-7554 or fax the request to 656-7630. (See Appendix A for forms)
b. Stockrooms/storerooms
Where stockrooms and storerooms exist, these conditions apply:
· Toxic substances should be segregated in a well identified area with local exhaust ventilation.
· Stored chemicals should be inspection periodically (at least quarterly) for replacement, deterioration, and container integrity. Areas of stockrooms where chemicals which may become dangerous or form dangerous by-products should be inspected monthly.
· They should not be used as preparation or re-packaging areas,
· They should be opened during normal working hours,
· They must be controlled by a manager.
c. Distribution
· When chemicals are hand carried, the container should be placed in an outside container or acid-carrying bucket to protect against breakage and spillage. Secondary containment is especially important when chemicals are moved in public areas, such as hallways or elevators.
· When they are transported on a wheeled cart, the cart should be stable under the load and have wheels large enough to negotiate uneven surfaces (such as expansion joints and floor drain depressions) without tipping or stopping suddenly.
· Freight-only elevators should be used if possible.
· Provisions for the safe transport of small quantities of flammable liquids include the use of rugged pressure-resistant, non-venting containers and elimination of potential ignition sources.
· All chemical containers being transported shall have labels identifying the contents and associated hazards.
d. Shipment: Hazardous materials shipments are subject to the regulations of the U.S.
Department Of Transportation (D.O.T.) until the containers are opened for use. Packages of hazardous materials may not be left unattended on a loading dock. Special DOT training is required for those persons who package and ship hazardous materials.
e. Laboratory storage
· All incoming containers of hazardous chemicals must have appropriate labels that are not removed or defaced.
· Each container should be labeled as to the date it was received and the date it was opened as some chemicals form peroxides or other unstable products when stored for relatively short periods of time. Refer to Appendix F for a list of common laboratory chemicals that may become unstable with time.
· Amounts permitted should be as small as practical. Storage on bench tops and in chemical hoods is not permitted.
· Chemicals in the laboratory should be segregated (see Appendix C) and safely stored. Acids, bases, corrosives, oxidizers, and toxics should be separated from one another by space and secondary containment.
· Flammable liquids should be kept in NFPA-approved flammable liquid storage cabinets (see Appendix C).
· Absolute ethyl alcohol must be stored in locked cabinets.
· Exposure to heat or direct sunlight should be avoided.
· Chemicals should not be stored under a sink.
· Strong acids or bases or unsealed toxic chemicals can be stored in ventilated base of chemical fume hoods but separation should be provided to prevent cross-mixing. Mild acids and bases such as citric acid and sodium carbonate may be stored with other low-hazard reagents.
· Open shelves for low-hazard, stable chemicals should be located out of normally traveled routes. The higher shelves should be used for smaller containers of the lowest hazard chemicals.
· Lecture bottles and full-sized cylinders of compressed gases should be stored in a ventilated storage area (see "Standards for Handling Compressed Gas Cylinders", Section V).
· Gas cylinders must be secured (strapped or chained). The area should have adequate room ventilation to remove leaking gas and easy accessibility for periodic exchange of cylinders. (See Section V for additional information on compressed cylinders including size and quantities allowed in laboratories)
f. Inventory: The laboratory or area supervisor, or his/her designee, must maintain a list of all hazardous chemicals known to be present in each laboratory or area and keep the list updated. Unneeded items should be discarded or identified as surplus (Refer to your "Hazardous Waste Management" Manual). The inventory must identify each hazardous chemical by the primary name on the label, manufacturer or distributor of the chemical, the Chemical Abstract Number (CAS), the quantity, and an indication of the availability of a Material Safety Data Sheet (MSDS) for that chemical. The inventory should be kept in a readily accessible location in a suitable format such as that illustrated in Appendix B. A hazardous chemicals inventory must be submitted to the Chemical Hygiene Officer (Naomi Kelly) by the 15th of February of each year.
5. Housekeeping, Maintenance, and Inspections
a. Housekeeping
· In the laboratory and elsewhere, keeping things clean and organized helps provide a safer environment.
Poor housekeeping increases the likelihood that an accident will occur and increases the total potential damage when accidents do occur.
· Keep drawers and cabinet doors closed and electrical cords off the floor to avoid tripping hazards.
· Keep aisles clear of obstacles such as boxes, chemical containers, and other storage items that might be put there even temporarily.
· Avoid slipping hazards by cleaning up spilled liquids promptly and keeping the floor clean.
· Never block or even partially block the path to an exit or to safety equipment, such as a fire extinguisher or safety shower.
· Put ordinary wastepaper in a wastepaper basket separate from chemical wastes or biohazardous wastes.
· Broken glass and other sharp items shall be disposed of in rigid, puncture-resistant containers to protect persons collecting the waste materials. These containers must be properly labeled. They should never be filled to the point where any material is protruding, or so that the weight of the carton would present a lifting hazard. Check to ensure that the container is intact and sound before attempting to lift. Securely tape the container before depositing in the dumpster. Ensure that only clean (no contaminated) glass is deposited to these containers.
· Even needles and syringes that are not contaminated should be placed in biohazard sharps containers provided by EHS, so that they may be disposed of safely.
· When discarding empty boxes or other containers bearing hazardous materials labels, the label shall be defaced or removed before disposal.
· Contaminated boxes or other containers shall not be disposed of in the regular trash.
b. Inspections
· Housekeeping and chemical hygiene inspections should be performed by researchers, departmental safety personnel, or lab managers at least monthly for units that have frequent personnel changes and quarterly for others; informal inspections should be continual. (See Appendix I for an inspection checklist which can be used as a guide in performing inspections)
· Eye wash stations must be inspected weekly. Inspection should include flushing each unit for a minimum of 3 minutes. Safety shower units should be inspected weekly, but must be inspected at least monthly. Safety showers should always be inspected immediately prior to using any highly corrosive chemical. Inspection of safety showers should include flushing each unit for 1-2 minutes or until water runs clear. Containers should be used to collect water from flushing of lines. A 55 gal. container on a wheeled-type canister with spout at the bottom is the best setup. Flushing water can be collected and released over a floor drain or outside. These inspections should be recorded on inspection tags on the equipment or inspection forms posted at or near the stations and should include the last date of inspection and initials of the inspector. If recording on inspection tags, ensure that they are not attached to the equipment in a position where they will be wet if the shower is activated.
c. Passageways: Stairways and hallways should not be used as storage areas. Access to exits, emergency equipment, and utility controls should never be blocked.
6. Personal Protective Apparel and Equipment (PPE)
Protective apparel compatible with the required degree of protection for substances being handled (follow labeling requirements and refer to MSDS). Users must be trained in the proper selection, use, cleaning, and maintenance of personal protective equipment (PPE). (Refer to Appendix H for additional information on PPE)
a. Eye and Face Protection
· Safety glasses must be worn by everyone, including visitors, who enters an area where chemicals are stored, handled or used. They must also be worn in areas where machines or operations create a flying particle/object hazard; areas where processes can produce aerosols; where hot liquids or molten metals are handled; gas or electric welding in done; cyrogenic materials are handled; explosive materials are handled, or injurious radiation is present.
· Regular eyeglasses and contact lenses do not provide adequate eye protection.
· For laboratory visitors, safety glasses with side shields are adequate. For laboratory workers, where the danger of chemical splash exists, splash goggles are required.
· For more hazardous operations, a combination of safety goggles or glasses and a faceshield should be used (i.e., handling corrosive chemicals, cyrogenic or hot liquids, where flying particles/objects are a potential hazard).
· Design, construction, tests, and use of eye and face protection purchased prior to July 5, 1994, must be in accordance with ANSI Z87.1-1968 USA Standard Practice for Occupational and Educational Eye and Face Protection. Protective eye and face devices purchased after July 5, 1994, must comply with ANSI Z87.1-1989, American National Standard Practice for Occupational and Educational Eye and Face Protection. To ensure that the protective eye and face devices you are using are approved by OSHA, look for Z87.1 stamped on the glasses. Be sure that all future purchases of eye and face protection are Z87.1-1989 ANSI approved.
See Appendix H for more information on safety eyewear, including information on University contract for prescription safety glasses.
b. Laboratory Coats/protective clothing
· Must be worn in areas where chemicals are handled or used (scrubs or similar apparel that will provide equivalent protection may be worn)
· Should be worn outside of laboratories only when transporting hazardous materials from lab to lab, stockroom, etc.
· They must not be worn in public or administrative areas of a building such as the offices, cafeteria/vending areas, lounges, etc.
· Are intended to prevent contact with the minor chemical splashes and spills encountered in a lab.
· Do not significantly resist penetration by organic liquids—intended for incidental splash protection
· Fabric should be selected by the laboratory activity—cotton or flame retardant lab coats should be used in laboratories where open flame is used or where large quantities of flammable chemicals are used. Polyester blends provide more chemical resistance, but tend to melt to your skin if they catch fire.
· Should be removed immediately when they become contaminated.
· Front opening laboratory coats should always be worn closed.
· When handling corrosive or irritating liquids, chemically-resistant aprons and sleeve covers provide better protection but can complicate injuries in the event of a fire.
· Home laundering of laboratory coats and other protective clothing is not permitted. A washer and dryer are available in Room 71 of the P&AS Building. (See Appendix M for info on Laundry Facility)
· Should be laundered routinely to prevent contamination from accumulation.
b. Hand Protection
· Hand protection is required for employees whose hands are exposed to hazards such as those from skin absorption of harmful substances; damage of skin by contact with a hazardous material; severe cuts or lacerations; severe abrasions; punctures; chemical burns; thermal burns; and harmful temperature extremes, i.e., cryogenic liquids).
· Select proper glove material based on the substance being handled, the particular hazard involved, and their suitability for the operation being conducted.
· Inspect gloves for discoloration, punctures, and tears before each use. If the gloves are to be reused, wash them before removal and replace them periodically.
· Always wash hands after removing gloves.
*See Appendix H for additional information
c. Respiratory Protection
· The Office of Environmental Health and Safety provides respiratory protection for situations where engineering and administrative controls cannot feasibly contain a respiratory hazard.
· If a respirator is needed, it must be issued from the Office of Environmental Health and Safety or the local safety officer at Clemson's research and education centers.
· The purchase of all respiratory protection equipment for use at Clemson University facilities requires prior approval by the Office of Environmental Health and Safety.
· Anyone whose work may require respirator use should follow the procedures outlined in University’s Respirator Protection Program. These include:
· Hazard evaluation
· Respirator selection
· Medical surveillance
· Respiratory training
· Fit testing
Refer to the University Respiratory Protection Program Manual for complete information or contact the University’s
Industrial Hygienist at 656-7557.
*See Appendix H for additional information.
d. Hearing Protection
· Exposure to high noise levels can cause hearing loss or impairment. It can create physical and psychological stress. There is no cure for noise-induced hearing loss, so the prevention of excessive noise exposure is the only way to avoid hearing damage. Specially designed protection is required, depending on the type of noise encountered.
· Preformed or molded ear plugs should be individually fitted
· Some earplugs are disposable, to be used one time and then thrown away. The non-disposable type should be cleaned after each use for proper protection.
· Earmuffs need to make a perfect seal around the ear to be effective. Special equipment is available for use with glasses or beards.
· For extremely noisy situations, earplugs should be worn in addition to earmuffs. When used together, earplugs and earmuffs change the nature of sounds; all sounds are reduced including one’s own voice, but other voices or warning devices are easier to hear.
· Contact Clemson University’s Industrial Hygienist at 656-7557 or EHS for information and assistance.
e. Head Protection
Head injuries are caused by falling objects, or by bumping the head against a fixed object. Head protection in the form of protective hats, must do two things:
1. Resist penetration
2. Absorb the shock of a blow
*See Appendix H for additional information.
Other Protective Equipment
· An easily accessible emergency shower and/or eyewash as indicated by chemicals stored and used.
· A proper fire extinguisher selected based on the materials, chemicals, equipment, etc. in your area. (If employees are expected and/or allowed to use fire extinguishers, they must be trained; contact the University Fire Department to schedule training for your department)
· Fire alarm and telephone for emergency use should be available nearby (preferably inside laboratories)
· Other items designated by the laboratory supervisor.
7. Records
a. Laboratory incident records should be written and retained. Please forward copies of these records to the University Chemical Hygiene Officer (Moorman House or email nkelly@clemson.edu).
b. Laboratory specific Chemical Hygiene Plan standard operating procedures, SOPs must be developed by laboratory supervisors and retained with the University Chemical Hygiene Plan. (See Appendix K)
c. Accurate records of the amounts of chemicals with high chronic and acute toxicity stored and used, the dates of use, and names of users should be retained.
d. Medical records are retained by the institution in accordance with requirements of state and federal regulations
e. Exposure monitoring records.
f. Records for perchloric acid hood use (how used, quantity, washdown cycle, etc.)
8. Signs and Labels
a. Prominent signs and labels of the following types should be posted:
b. Emergency telephone numbers of emergency personnel/facilities, supervisors, and laboratory workers; This information should be posted at lab entrances (on or beside doors). Emergency response numbers should also be posted (preferably both inside—near phone and outside the lab). Information about the hazards (i.e., Biohazards, Radioactive materials, carcinogens, flammable, water reactive, etc.) that exist in the lab should be posted. General lab rules should also be posted: NO FOOD OR BEVERAGE ALLOWED; NO SHORTS, SHORT SKIRTS, SANDALS, OPEN SHOES, ETC. ; SAFETY GLASSES AND LAB COATS MUST BE WORN BY ALL LAB PERSONNEL; VISITORS MUST WEAR SAFTEY GLASSES; NO VISITORS ALLOWED WITHOUT PERMISSION FOR AUTHORIZED PERSONNEL; VISITORS MUST BE ACCOMPANIED BY AUTHORIZED PERSONNEL
c. Identity labels, showing contents of containers (including waste receptacles) and associated hazards;
d. Location signs for emergency showers, eye wash stations, other safety and first aid equipment, exits and areas where food and beverage consumption and storage are permitted;
e. Areas where hazardous materials are handled or stored must be posted with proper hazard warning signs (See “Signs and Labels”, Appendix E).
9. Spills and Other Laboratory Incidents
a. A written emergency plan should be established and communicated to all personnel;
b. It should include procedures for ventilation failure, evacuation, medical care, reporting, and drills.
c. There should be an alarm system to alert people in all parts of the facility including isolation areas such as walk-in cold rooms.
d. A spill control policy has been developed and includes consideration of prevention, containment, cleanup, and reporting (see Appendix D).
e. All accidents or near accidents should be carefully analyzed with the results distributed to all who might benefit.
10. Waste Disposal Program
Assure that the plan for each laboratory operation includes plans and training for waste disposal. Indiscriminate disposal of waste chemicals down the drain or by adding them to mixed refuse for landfill burial is unacceptable and illegal. The University’s Hazardous Waste Management Manual describes acceptable waste disposal methods at Clemson facilities
a. Chemical hoods may not be used as a means of disposal for volatile chemicals.
b. Before a worker's employment in the laboratory ends, chemicals for which that person was responsible must be reassigned, properly discarded or identified as surplus.
c. Indiscriminate disposal by pouring waste chemicals down the drain or adding them to mixed refuse for landfill burial is both unacceptable and illegal.
d. Recycling should be used when possible.
e. An attempt should be made to make available to other laboratories, chemicals which are no longer useful in your laboratory, but may be useful to others
f. Contact the University’s Hazardous Waste Manager for details about these procedures for a particular waste.
11. Synthesized Chemicals
If hazardous chemical substances are developed in the laboratory for in-house use, appropriate training should be given to personnel as with any other hazardous chemical. If the chemical produced is a by-product whose composition is not known, it shall be assumed that the substance is hazardous and should be treated in the same manner as other hazardous chemicals.
B. Laboratory Specific Operating Procedures
Place laboratory specific chemical Safe Operating Procedures (SOPS) here. (For guidelines on developing individual laboratory SOPs, See Appendix K)
IV. Ventilation.
A. General Requirements
· General laboratory ventilation. The system should: Provide a source of air for breathing and for input to local ventilation devices; it should not be relied on for protection from toxic substances released into the laboratory; ensure that laboratory air is continually replaced, preventing increase of air concentration of toxic substances during the working day; direct air flow into the laboratory from non-laboratory areas and out to the exterior of the building.
· Modifications. Any alteration of the ventilation system should be made only if thorough testing indicates that worker protection from airborne toxic substances will continue to be adequate. Any modifications to the lab ventilation system must have the approval of EHS.
· Performance. Six to twelve room air changes per hour is normally adequate general ventilation if local exhaust systems such as fume hoods are used as the primary method of control. Air handling systems in University buildings that house laboratories were originally engineered and constructed to properly function with laboratory doors closed. Doors to the laboratory must be kept closed to ensure correct airflow.
· Quality. General air flow should not be turbulent and should be relatively uniform throughout the laboratory, with no high velocity or stagnant air.
1. Chemical Hoods
Chemical hoods are critical to the safety of laboratory personnel and the advancement of research throughout the University. They are the most important component used to protect laboratory workers from exposure to hazardous chemicals and other agents used in the laboratory. When properly installed, maintained, and used, they can provide protection from these hazards. When this does not occur, the health and safety of laboratory workers and maintenance personnel can be severely compromised, and research can be hindered.
a. The purchase, relocation, installation, or modification of all laboratory hoods or other ventilation device requires prior approval by the Office of Environmental Health and Safety and University Facilities.
b. Airflow into and within the fume hood should not be excessively turbulent; chemical hood face velocity should be adequate (typically 100-150 feet per minute) at an 18” sash height. Air disturbances at the face of the fume hood should be avoided. Face velocities for chemical hoods must be a minimum of 60LFM at a full open sash height. Velocities should typically not exceed 150lfm due to increased turbulence which can result in deceased capture efficiency.
c. Quality and quantity of ventilation should be evaluated on installation, regularly certified (at least annually), and re-certified whenever corrections or repairs are made or in the event that the hood is relocated. These certifications will be performed by EHS. If your fume hood certification is not up to date, or needs re-certification because of relocation or repairs, contact EHS (656-7557).
d. Close the fume hood sash when the hood is not in use. Work with the sash at the lowest possible position when using the fume hood. A working sash height of 18" or lower is recommended. Sash should not be raised above 18” except when necessary to place equipment in/out of the hood.
e. Chemical hoods should be kept clean and uncluttered. Achieving even, laminar airflow across the deck or bench surface of the hood increases the effectiveness of the hood system. The presence of objects in the hood tends to increase turbulence in the hood. For this reason, the number of objects in a hood should be kept to a minimum. In particular, keep chemicals out of the hood unless they are in immediate use. Not only does storage of chemicals in a hood decrease the efficiency of the hood, but it also increases the possibility and seriousness of accidental fires/explosions.
f. Work within the hood, at least six inches back from the front opening. This greatly improves the capture rate for volatile materials. Paint a line or place a strip of tape 6” inside the hood as a useful reminder. One’s face should never be within the plane of the sash when working with chemicals in the hood.
g. Run water in hood drains at least once a week if the drains are not normally used.
h. Conduct all operations inside a fume hood when working with hazardous chemicals which may generate air contaminants. Work with all hazardous chemicals, regardless of Permissible Exposure Level (PEL) or Threshold Limit Value (TLV), should be handled under a chemical fume hood whenever possible.
i. Take care not to obstruct airflow by the arrangement of equipment and materials in the hood.
j. Do not use the hood as a waste disposal mechanism.
k. Do not store chemicals or non-essential apparatus or equipment in the hood. Store hazardous chemicals in an approved safety cabinet.
l. Hoods should always be "ON" if chemicals if chemicals are being used in the hood (if chemicals are in the hood, they are considered as being used because they should not be in the hood unless they are in immediate use; or, if chemicals stored in cabinets under the hood require ventilation.
m. Motor-driven electrical equipment used in a fume hood where volatile flammable materials may be present must be equipped with a non-sparking induction motor.
n. Keep the slots in the hood baffle free of obstruction by apparatus or containers.
o. Minimize the floor traffic past the face of the hood and avoid making rapid movements while standing in front of the hood. Turbulence caused by an individual in front of an open hood can greatly enhance exposure.
p. Work requiring the mixing, stirring, heating, grinding or any other operation that could reasonably be expected to cause aerosolization of hazardous materials should be performed in fume hood.
q. Ideally, each fume hood should have a continuous monitoring device to allow convenient confirmation of adequate fume hood performance. If a hood does not have properly operating alarm installed on the hood, attach a piece of tissue (Kim-wipe) to the each corner of the sash. This will at least give some indication of air flow (and will definitely let you know if there is no flow) until the proper monitor can be installed. Do not use the hood if monitoring devices indicates that the hood is not working properly.
r. Must be properly ducted to the outside of the building, with proper stack height to ensure that no re-entrainment into the building or any surrounding building occurs.
s. Sinks incorporated into the hood surface should have a retaining edge surrounding them in order to prevent leaks/spills inside the hood from being released to the sewer system.
t. Airfoils should be installed at the front edge of the floor of all hoods. This airfoil serves to minimize the effect of turbulence as air enters the hood. Airfoils currently installed on hoods should not be removed.
u. Keep laboratory doors and windows closed. In closed buildings, ventilation systems are usually designed on the assumption that laboratory doors and windows will be in the closed position. If the doors and windows are left open, unplanned airflow patterns may degrade the efficiency of the hood.
v. The sash glass offers protection from accidents and, when possible, it is safest to keep the sash between your face and the experiment. However, the sash is not designed to protect against explosions. When an explosion hazard is present, rounded safety shields should be placed between the operator and the experiment and as close as possible to the plane of the hood sash. Full-face protection should also be used in such circumstances.
2. Hood Failure Procedures
a. Immediately stop all work in the hood.
b. If possible, stabilize reactions and turn off equipment (i.e., hot plates) or other electric devices to avoid unplanned re-energizing of this equipment when the hood power is reactivated. Close any opened/exposed containers of chemicals or radioactive materials currently under the hood.
c. Close the hood sash
d. If processes/reactions cannot be stopped/contained, the lab(s) should be evacuated until hood(s) are operating.
e. Do not use the hood until repairs have been made and the hood is re-tested and approved for use by EHS (at which time the “DO NOT USE” sign will be removed.
f. Report the problem to:
1. The Director of the Lab and/or the Building Manager
2. University Facilities (656-2186)
Notify others in the area and on additional shifts that the hood is not operating and cannot be used. The hood should be posted with a sign that boldly states that the hood is not functioning and should NOT be used until repairs/corrections have been made and sign is removed.
3. Types of Chemical Hoods
a. Conventional Fume Hood
This is a basic enclosure with a moveable front sash and an interior baffle. There can be additional slots in the baffle, perhaps one in the middle and one near the top, through which air can pass to provide more uniform airflow. The remaining air passes through the hood interior and is directed into the exhaust portal over the top of the interior baffle. The performance of the hood is dependent on sash position.
b. By-Pass Hood
The by-pass air hood is quite similar to the conventional hood, except that it is designed to permit some exhaust air to “by-pass” the sash closure. This has two consequences. The first is that the air velocity near the work surface remains reasonably constant, so that excessive air speeds will not occur. The second is that there is less static pressure and hence less frictional resistance to the flow of air than with the conventional hood, so that the volume of air through the hood remains more nearly the same at different sash heights, permitting better control of the laboratory air balance.
c. Auxiliary (Make-Up) Air Hood
The auxiliary air hood provides a means of introducing outside air to the hood exhaust and limits the percentage of tempered air removed from the laboratory. Usually, the auxiliary system supplies air downward across the sash and into the hood opening. The installation and configuration of this type of hood is critical and proper operation is difficult to maintain. It is also very difficult to accurately measure face velocities with this type of hood. We do not recommend the use of this type of hood and do not allow new installations of auxiliary air hoods.
d. Walk-in Hoods
Walk-in hoods are hoods which usually rest directly upon the floor or on a pad
resting directly upon the floor. They are designed to accommodate tall
appratus which will not fit in a standard hood sitting upon a base unit or
bench. Because their height would require an abnormally long sash travel,
these hoods are often provided with dual sashes, each of which would cover
half the opening or with a single sash which would come down only about
halfway, with swinging doors being used to provide access to the lower
portion.
3. Special Purpose Chemical Hoods
a. Perchloric Acid Hood
Due to the potential explosion hazard of perchloric acid when combined with organic materials, this hood type must be used for perchloric acid digestion. It must be constructed of relatively inert materials such as type 316 stainless steel, ceramic coated material, or PVC. Hoods used for these applications should have integral bottoms, covered interiors, and a drain. Wash down features are required since the hood and duct system must be thoroughly rinsed after each use to prevent the accumulation of reactive residue. Perchloric acid hoods are by their nature of the by-pass type. The hood should be prominently labeled with a sign stipulating that it is for perchloric acid work only. Exhaust systems serving hoods used with heated perchloric acid should not be manifolded into a common exhaust plenum.
b. Radioactive Hood
Hoods used for radioactive applications should have integral bottoms and covered interiors to facilitate decontamination. These units should also be strong enough to support lead shielding bricks, in case they are required. These hoods are also of the by-pass type.
Chemical hoods used for radioactive materials should be marked “RADIOIOSTOPE HOOD” and in addition should be labeled with a “CAUTION-RADIOACTIVE MATERIALS” sign bearing the standard radiation symbol. The isotopes being used should be identified on the label.
c. Ductless Hoods
Occasionally, EHS is asked to approve the purchase of a ductless hood for use in labs. These hoods are designed to remove hazardous vapors from the work area as the exhausted air passes through an absorbent, such as activated charcoal. These hoods require constant attention and often do not provide adequate face velocity. The filters are designed for specific chemicals and will not protect against the variety of chemicals used in a typical university lab. Ductless hoods are plagued with the problems associated with “breakthrough” and with desorption of vapors from the absorbent. The user is also faced with expenses to replace filters and dispose of the expended filters. Routine monitoring is also required to ensure that “breakthrough” is no occurring and users are not being overexposed. We, therefore, will not approve ductless hoods and will not provide inspection or certification for these hoods.
4. Other Ventilation Devices
a. Ventilated storage cabinets, canopy hoods and snorkels should be provided as needed, provided they are installed properly and with the approval of the Office of Environmental Health and Safety. Each canopy hood or snorkel should have a separate exhaust duct. Canopy hoods have their uses, where it is desired to capture and exhaust hot fumes carried upward by convention currents until they come close enough to the canopy so that the fumes become entrained within the hood. The speed of the air movement in the vicinity of the hood face, due to the air flowing through the canopy, falls off very rapidly to about 7.5% at a distance equal to the effective size of the canopy opening. If the canopy is at a reasonable distance away from the bench top, the airflow at the work surface due to the hood will be on the order of the average air movement speed within the room, or less. A further disadvantage would be that the fumes, if drawn upward, would pass through a worker’s breathing zone. For these reasons, canopy hoods are not recommended as general usage laboratory fume hoods.
b. Any ventilation used to control the release of hazardous substances must be exhausted to a once-through system; not recirculated into the building’s general atmosphere.
c. The University does not allow the use of ductless fume hoods except in very limited circumstances that must be approved by EHS. They can be utilized in a laboratory if chemicals to be used in the fume hood are non-volatile particulates that can be effectively captured by the HEPA filtration system, if the HEPA filtration pack is changed frequently, and if the system is properly maintained. These systems should never be used for highly toxic material. Usage of the ductless chemical hood is generally not allowed because there is no established mechanism to periodically test these units. Therefore, there is no way to determine when the filter is saturated. Also, the chemical vapor may be gradually released into the lab from these filtration substrates, unknowingly exposing the laboratory occupants.
5. Biological Safety Cabinets
The biological safety cabinet is the principal device used to provide containment of infectious splashes or aerosols. Biological safety cabinets are divided into three classes based upon the type of protection provided. Class I and II cabinets use an air curtain and Class III uses as physical barrier to protect personnel. Class II and III cabinets filter the air before it is blown onto the work surface, and all three have filtered exhaust. HEPA (high efficiency particulate air) filters are used since they are efficient in removing at least 99.97% of particles 0.3 microns in diameter or greater. HEPA filters do not remove gaseous contaminants. As the filter becomes loaded, the resistance to air movement through the filter increases, with the result that the rate of air flow will decrease. Therefore, airflows must be adjusted periodically to assure proper performance. Also, these cabinets are subject to the same requirements with regard to location as fume hoods.
Biological safety cabinets must be tested and certified after installation and before use, any time they are moved, and at least annually. Certification of biological safety cabinets will be performed by a certified agent contracted by EHS. Costs for certification and necessary replacement of HEPA filters will be billed back to individual departments. If your biological safety cabinet needs to be certified/recertified, contact the University Biological Safety Officer at 656-1806.
For specific information on the three classes of biological safety cabinets, refer to Clemson University’s Biological Safety Manual or contact the University Biological Safety Officer.
6. Horizontal or Vertical Laminar Flow Cabinets
Horizontal or vertical laminar flow cabinets (clean benches or blow out hoods) are not biological safety cabinets or chemical fume hoods. They lack a front window and provide protection for only the work surface, not the worker. Clean filtered airflow is forced across the work area and either directly or indirectly blown at the worker, and therefore these cabinets should not be used for work with potentially hazardous materials, including antibiotics used during media preparation.
7. Special Ventilation Areas
a. Glove boxes are usually small units that have multiple ports in which arm-length rubber gloves are mounted, and the operator works through these. Glove boxes generally operate under negative pressure, so that any air leakage is into the box. Exhaust air from glove boxes and radioactive iodine fume hoods should be passed through scrubbers or other treatment before its release.
b. Isolation rooms use the same principles as glove boxes, except that the protected worker is within the unit. The unit itself operates under negative pressure, and the exhaust air requires special treatment before release.
B. Laboratory Specific Ventilation Requirements
Place laboratory specific ventilation requirements, here. Contact Clemson University’s Industrial Hygienist for information and assistance with these requirements.
V. STANDARDS FOR HANDLING COMPRESSED GAS CYLINDERS
A. INTRODUCTION
Users of compressed gases should be familiar with the pertinent equipment and the characteristics of the gases. Gases are supplied in cylinders under great pressures, some as much as several thousand pounds per square inch. If the valve is broken off a the cylinder neck, the cylinder becomes a potentially deadly rocket, propelled with great momentum and high speed. Gas cylinders have been documented to cause extensive property damage, injury, and death. For this reason, all gas cylinders, full or empty, must always be strapped or chained to a sturdy support to prevent the cylinder from falling and breaking off the valve. All cylinders of compressed gas should be treated as high-energy sources and therefore regarded as potential explosives. The contents of a cylinder may also present such hazards as flammability, toxicity, corrosivity, excessive reactivity, and potential asphyxiation (if the volume of air displaced by the contents of the cylinder is sufficient).
Compressed gas:
· Any material or mixture having in the container an absolute pressure greater than 40 psi at 70F or
· Regardless of pressure, one having an absolute pressure greater than 104 psi at 130F, or
· Any liquid material having a vapor pressure greater than 40 psi absolute at 100F
Hazard Categories:
The hazards of compressed gases can be categorized into the following basic hazards:
· Inerts which displace oxygen causing simple asphyxiation (e.g., nitrogen, argon, and helium)
· Toxics which cause adverse health effects depending on the type of gas, route entry, and dose. (e.g., phosgene and CO)
· Flammables which cause fire or explosion when ignited. (e.g., CO, CH4, and H2)
· Reactives which can be subdivided into:
a. Corrosives that erode and deteriorate human flesh, or equipment
b. Oxidizers that are not flammable by themselves, but which react violently with flammable or combustible materials
(Many gases fall into more than one category.)
Hazards can result from improper handling of gas cylinders and high pressure equipment, which exist in many University facilities. For example, a leaking cylinder could produce an atmosphere that is toxic, anesthetic, asphyxiating, or explosive; and in the event of a rapid escape, the cylinder becomes a randomly directed missile. The main purpose of properly handling compressed gases is, therefore, to prevent uncontrolled escape of the gas. All handling, storage and utilization of compressed gases must comply with the Compressed Gas Association Standards.
The following information is offered in order to familiarize personnel with cylinder parts and terminology:
1. Valve handwheel: used to open and close the cylinder valve. Valves are occasionally not
equipped with handwheels and require special wrenches to effect operation.
2. Valve pack nut: contains packing gland and packing around stem. Adjusted only
occasionally; usually tightened if leakage is observed around valve stem. Should not be
tampered with for diaphragm-type valves.
3. Valve outlet connection: for connection to pressure-and/or flow-regulated equipment.
Various types of connections are provided to prevent interchange of equipment for
incompatible gases. Usually identified by a CGA (Compressed Gas Association) number,
for example, No. 350 for hydrogen service.
4. Safety device: to permit gas to escape if the temperature gets high enough to endanger the
cylinder by increased unsafe pressures.
5. Cylinder collar: holds cylinder cap (6) at all times, except when regulating equipment is
attached to cylinder valve.
6. Cylinder cap: to protect cylinder valve.
7. DOT number: This number signifies that the cylinder conforms to Department of
Transportation specification DOT-3A governing materials of construction, capacities, and
test procedures; and that the service pressure for which the cylinder is designed is 2,000
pounds per square inch at 70oF.
8. Hydrostatic Test Date:This number indicates the date (month and year; in this case, June
l965) of initial hydrostatic testing. Thereafter, hydrostatic pressure tests are performed on
cylinders. For most gases this is done every five years to determine their fitness for further
use. At this time, new test dates are stamped into the shoulder of the cylinder. Present
regulations permit visual tests in lieu of hydrostatic tests for low-pressure cylinders for
certain gases free of corrosive agents. Special permits allow for hydrostatic pressure tests at
ten-year intervals for cylinders in high-pressure service for certain gases.
10. Original inspector's insignia: for conducting hydrostatic and other required tests to
approve the cylinder under DOT specifications.
11. Valve outlet cap: protects valve threads from damage and keeps outlet clean; not used
universally.
B. GENERAL STANDARDS
The rules for handling cylinders are relatively simple and straightforward. If they are followed, most serious accidents will be eliminated.
1.All cylinders must be marked as to content. Do not accept cylinders with unidentifiable
contents.
2.Unless the pressure regulator is attached, keep the valve protection cap on securely.
3.Cylinders must be secured with heavy-duty chains, at about 2/3 the height of the cylinder, to
prevent them from falling. Chains should be used to ensure that cylinders remain upright in the
event of a fire.
4.Do not store full and empty cylinders together. Serious "suckback" can occur when an empty
cylinder is mistakenly attached to a pressurized system.
5.Group cylinders by type of gas. For example, store oxidizing gases at least 20 feet away from
flammable gases.
6.Cylinders must not be stored near sources of heat, ignition, oil, grease, or where they might
become part of an electric circuit.
7.Protect from direct rays of sun.
8.Cylinders can be stored in the open but should be protected from the ground beneath to
prevent rusting.
9.Bond and ground all cylinders, lines, and equipment used with flammable compressed gases.
10.Limit the storage of corrosive gases to about three months. The cylinder valve stem should be
worked frequently to prevent freezing. The valve should be closed when not in use.
11.Cylinders should not be subjected to low temperatures because many steels undergo
decreased ductility at low
temperatures and could crack.
12.Avoid subsurface storage locations.
13.Before connecting a regulator, the cylinder valve should be opened slightly and closed
immediately unless the gas is toxic.
14.Do not try to force a regulator to fit the cylinder. A poor fit probably indicates that the
regulator is not intended
for use with that particular compressed gas.
15.Never use an adapter fitting.
16.Open the cylinder valve slowly. Rapid release of a compressed gas will cause an unsecured
gas line to whip dangerously and also may build up a static charge which could ignite a
combustible gas. Never direct high pressure gases at a person, or use compressed gas or
compressed air to blow away dust, etc.
17. Never attempt to repair or alter cylinders, valves, or safety relief devices.
18. Do not wipe or touch the valve outlet of an oxygen cylinder valve in such a way that organic
residues which might be subsequently ignited by exposure to high oxygen pressure are
deposited.
19. DO NOT EMPTY A CYLINDER COMPLETELY. This will prevent a "suckback" and a
possible explosive mixture.
20.When discharging gas into liquid, a trap or suitable check valve must be used to prevent
liquid from getting into the cylinder or regulator.
21.Do not use copper tubing with acetylene.
22. Never drag or roll cylinders, even for short distances. Move cylinders only on a handtruck.
Use chains to secure them to the handtruck. Do not lift cylinders by the cap.
23. Never drop cylinders or allow them to strike each other sharply.
24. Cylinders must not be charged except by the vendor.
25. Use soapy water or a commercial leak detector to detect gas leaks.
26. Employees must not attempt to repair cylinders or cylinder valves or to force stuck or frozen
cylinder valves.
27. Always wear safety goggles when handling or using compressed gases.
28. Only those tools approved by the cylinder vendor should be used on cylinder connections.
Do no modify or alter cylinders or their attachments. Use cylinders and manifold systems
only with their appropriate pressure regulators.
29. Always use a trap to prevent back siphonage of liquid chemicals, and a check valve to prevent back flow of Gases into the cylinder. When gas is passed from a cylinder into a vessel containing a liquid, contamination
of the cylinder gas with other chemicals is a real possibility. Such contamination makes the gas unsuitable for future use and may result in explosion with resultant injury, damage, or even death. Use of a safety trap to contain liquid and a check valve to prevent back flow of gas will eliminate this possibility. These are installed immediately after the pressure regulator, and before the vessel containing the liquid. The safety trap should have a volume of about one and one half times the total liquid volume in the system.
30. Use cylinders only in well ventilated areas. Corrosive gases should be used only in locations
with access to safety showers and eyewash stations. Corrosive, toxic, and flammable gases should be used in chemical hoods
designed for use with that particular gas or group of gases. Use flammable gases only after
proper bonding and grounding connections have been made.
31. Do not expose cylinders to temperatures higher than about 50C(122F). Some rupture devices on cylinders will
Release about 65C (149F). Some small cylinders, including those not fitted with rupture devices, may explode if exposed to high temperatures.
32. Transport cylinders in freight-only elevators, if possible. If transport in a passenger elevator is necessary,
Perform a leak test prior to placing the cylinder into the elevator. Do not allow other passengers onto the elevator until you reach your destination and the cylinder is removed. Alert someone on the floor to which to you are transporting the cylinder and have them meet and assist you. In the event that there is an electrical failure, and you are stalled in the elevator; the employee scheduled to meet and assist you would then report the elevator being stalled with an employee and a compressed gas cylinder on board (they should also have information about the contents of the cylinder, etc.)
C. RESTRICTED PRODUCTS (TOXIC GASES)
1. Highly toxic gases may be purchased and used only upon written permission of the Institutional Biosafety Committee. Notification of intent to work with highly toxic gases must be made prior to their proposed purchase to allow time for assuring that physical facilities and work practice controls are sufficient for the expected hazard. Large cylinders of toxic gases should not be purchased if it is possible to use small cylinders.
2. Some of these gases are extremely toxic and may require isolated laboratory space and equipment not immediately available. For this reason, clearance should be requested well in advance of the proposed use. Examples of gases considered to be extremely toxic are chlorine, arsine, boron trifluoride, bromine, fluoride, phosgene, and phosphine. There are many others which are not listed here.
3. Storage of highly toxic or poison gases must be outdoors, or in a well-ventilated noncombustible building without other occupancy, or in a well-ventilated, separate room without other occupancy, and of noncombustible construction with a fire resistance rating of at least one hour. Storage locations must be clearly marked and protected against tampering or entry by unauthorized persons.
4. The total quantity of highly toxic gases stored should be limited to immediately foreseeable requirements. They should be stored in ventilated cabinets. Allowable quantities are listed in the table at the end of this section.
5. All personnel working in the immediate must be instructed as to the toxicity of the gas or gases being used or stored, the appropriate methods of protection against harmful exposure, and first aid treatment in case of exposure.
6. Because of the hazardous nature of highly toxic and poisonous gases, persons handling such gases are advised to contact the supplier for more complete information than will be found on the material safety data sheet with regard to usage and first aid.
7. The maximum quantity and size limitations for cylinders of highly toxic gases are listed in the table at the end of this section.
8. Do not transport cylinders containing toxic gases in passenger elevators.
D. FLAMMABLE GASES (HYDROGEN, ACETYLENE, AND OTHERS OF THIS CLASSIFICATION)
Because of the fire and explosive hazards that can result when these products are used in confined spaces, special care must be used.
1. When cylinders are kept inside the building, two or more cylinders should not be manifolded together. However, several instruments may be operated from one cylinder.
2. Considerations for the number of highly flammable gas cylinders to be placed in a laboratory room will include size of the room, airflow, other equipment in use, ease of access to cylinders, etc. The quantity and size of cylinders in laboratory work areas shall comply with NFPA regulations (see the table at the end of this section).
3. Standby cylinders of flammable gases (full reserve cylinders) or empty cylinders must not be stored in the laboratory. Cylinders will be stored out of doors and delivered to the laboratory on demand. (This does not change the responsibility of the user to initiate purchase orders.) Empty cylinders will be removed from the laboratory when the full cylinders are received.
4. When practical, valves on flammable gas cylinders should be closed before all employees leave the laboratory at night.
5. Adapters may be used only upon written permission of the Office of Environmental Health and Safety.
6. Piping must be compatible with the gas, (e.g., no copper for acetylene; no plastic tubing in any high pressure portion of a system, etc.)
E. ACCEPTANCE OF CYLINDERS FROM VENDORS
1. The contents of cylinders must be identified with decals, stencils, glued or wired-on tags, or other markings on the cylinders. Color codes alone or tags hung around the necks of the cylinders must not be used. Cylinders lacking proper identification must not be accepted from the vendor.
2. Cylinders must not be accepted from the vendors unless the valve safety covers are in place and properly tightened.
3. Vendors moving cylinders into University buildings must use hand trucks, carts, or dollies; cylinders must not be dragged or rolled.
4. Cylinder valves must conform to standards of the National Compressed Gas Association.
F. HANDLING AND STORAGE OF CYLINDERS
1. HANDLING
a. Cylinders should never be dropped or permitted to strike each other violently.
b. The valve safety covers must be left on the cylinders until they are secured to walls, benches, or stable pieces of equipment, or until non-tip bases are attached.
c. Cylinders must be transferred only by carts, hand trucks, or dollies. They must not be rolled or dragged. The valve safety covers must be in place and the cylinders secured to the carts during transport.
d. Cryogenic containers of twenty gallon capacity or more should be transported only on 4-wheeled carts designed for that purpose.
e. Empty cylinders must be marked "EMPTY" or "MT" with grease pencils. Generally, this marking should be on a large piece of adhesive or masking tape stuck on the cylinder rather than on the tank itself. However, some cylinders have tags wired to the valve that identify their contents; in this case, the bottom half of' this tag may be torn off to indicate an empty cylinder. In all cases, empty cylinders must be easily identified so as not to be confused or stored with full cylinders.
2. STORAGE
Storage of gas cylinders is an important factor in gas safety. Always assign a definite area
for cylinder storage.
a. Store them upright in racks.
b. Keep the area cool, dry, and well-ventilated. Dryness avoids rust and corrosion, and makes maneuvering around storage areas safer. Avoid heat or direct sunlight. Prevent sparks and temperatures greater than 130F, particularly around flammables.
c. Cylinders that are necessary for current laboratory requirements shall be stored in a proper cylinder storage area.
d. Cylinders of all gases having health hazard ratings of 3 or 4 and cylinders of gases having a health hazard rating of 2 with no physiological warning properties shall be kept in a continuously mechanically ventilated hood or other continuously mechanically ventilated enclosure. There shall be no more than three cylinders of gases with health hazard ratings or 3 or 4 per hood or other enclosure.
e. The quantity and size of cylinders in laboratory work areas shall comply with NFPA standards (see Table at the end of this section).
f. Keep cylinders away from live electrical equipment. Any electrical spark to the cylinder can present heat and weaken the steel at that spot. Ventilation is necessary in case of leaks.
d. Separate full and empty cylinders. Empty cylinders should be marked to indicate that they are empty.
e. Separate non-flammables and oxidizers from flammables by at least 20 feet or by a noncombustible barrier having a fire rating of at least one hour.
f. Smoking is not allowed near flammables or oxidizers.
g. Cylinder storage areas should always be secured. Cylinders should always be strapped or chained.
h. NFPA recommends that corrosive gases not be stored for longer than six months. Examples of corrosive gases are: boron trichloride, boron trifluoride, bromine trifluoride, carbonyl fluorine, carbonyl sulfide, chlorine, chlorine trifluoride, fluorine, hydrogen bromide, hydrogen chloride, hydrogen fluoride, hydrogen iodide, hydrogen selenide, hydrogen sulfide, iodine pentafluoride, nitrogen dioxide, nitrogen tetroxide, nitrogen trioxide, nitrosyl chloride, phosgene, phosphorous pentafluoride, and sulfur tetrafluoride.
i. 1,3-butadiene, ethylene oxide, vinyl bromide, vinyl chloride, and vinyl fluoride should not be stored for longer than six months because problems may arise due to polymerization. Note: ethylene oxide should not be stored for more than three months unless provisions are made for refrigerated storage.
G. PRESSURE REGULATORS AND NEEDLE VALVES
1. The valve fittings of cylinders used to store different families of gases are different and will only allow regulators or needle valves to be attached that are safe for use with those gases. Cylinders must not be purchased or accepted whose fittings do not conform to standards of the National Compressed Gas Association. Use of adapters to connect regulators to cylinder valves defeats this safeguard and must not be used without written permission of the Office of Environmental Health and Safety. Only pressure regulators and needle valves approved for the gases may be used.
2. Threads and points of unions must be clean; these surfaces must be inspected before they are connected. Personnel must not attempt to lubricate threads or fittings.
3. When attaching regulators or needle valves, personnel must tighten the connections firmly. Non-adjustable wrenches of the proper size should be used. Pliers or adjustable wrenches should not be used, as they damage the nuts, most of which are brass and rather soft. Need for excessive force often indicates that the regulators or needle valves do not fit the cylinders. Leaks at the unions between the regulators and the cylinder valves are usually due to damage to the faces of the connections. Attempts to force a tight fit may damage the previously undamaged half of the connection. If the cylinder valve faces are damaged, the cylinders must be returned to the vendor. Employees must not attempt to repair them. Damaged regulators must not be used until repaired.
4. After attaching the pressure regulator to the cylinder, personnel should turn out the delivery pressure adjusting screws of the regulators until they turn freely. The cylinder valves should be opened slowly. Laboratory personnel should avoid standing directly in front of the regulators at this time as the pressure of the cylinders may blow the glass from the front of a faulty gauge. The cylinder valve handles should be left attached to the valves while the cylinders are in use. Cylinder valves that "stick" and do not open when the usual amount of force is applied may be damaged. Personnel must not attempt to force them open, but should return these cylinders to the vendors, stating on the cylinders that the valves are stuck.
5. Pressure in full cylinders should be as indicated on the cylinders or labels. Lack of full pressure may indicate leaks at the connections between the cylinders and valve regulators, damaged regulators, or incompletely filled cylinders.
6. Employees should connect delivery lines to the low pressure outlets of the regulator valves or to the needle valves. Where low pressure lines are used, their valves should be closed and line pressure adjusted by turning the regulator delivery pressure adjusting screws until the desired pressures are shown on the delivery pressure gauges.
7. If the gases are not to be used over a considerable length of time (i.e., 24 hours), the cylinder valves should be closed, the lines bled, and the pressure adjusting screws turned back until they turn freely. Damage to the gauges may result if pressure is left on the gauges during extended periods of nonuse.
H. LEAK TESTING
1. Leak testing using "snoop" or a soap solution should be done twice. The first test
should be made before the regulator or needle valve is attached to determine if
there are leaks at the union of the cylinder and the cylinder valve and to determine
if the valve is leaking. The second test should be made after the regulator is
attached and the cylinder valve is opened to detect leaks around the valve
stem packing, the connecting fittings, the regulator or needle valve, and the
transfer lines to the instrument.
2. Compressed gas cylinders are tested for leaks when they are filled; however, leaks have been detected when new cylinders were received in Clemson laboratories. Personnel should not attempt to repair cylinder leaks or leaks caused by loose valve stem packing. Leaking cylinders of nontoxic, nonflammable gas may be taken to a loading dock or other place having suitable air flow for the vendors to pick up. Leaks from cylinders of toxic or flammable gases require immediate attention. Decisions of how to handle the problem will depend on the kind of gas, the size of the leak, the area where the cylinder is located, and other factors. Personnel must wear gas masks or SCBA and appropriate protective clothing when attempting to move leaking cylinders of toxic gases. Only trained personnel who have been approved to wear respiratory protective gear would be allowed to handle leaking cylinders of toxic gases.
Report leaking or damaged cylinders to the University Fire Department at 911. As
always, when an accident or emergency situation:
* Remain calm.
* Give your name
* Report your location
* Describe the nature of the emergency (e.g., leaking high-pressure cylinder of toxic gas)
NOTE: Do not attempt to move a leaking or damaged high pressure cylinder even if it is not toxic gas unless you have been specifically trained to do so and have the necessary protective equipment and personnel back up present.
I. EMPTY CYLINDERS
1. A small amount of gas must be left in the cylinders and the cylinder valves must be closed to prevent contamination of the inside of the cylinders.
2. Empty cylinders should be marked "EMPTY" or "MT" and stored apart from full cylinders.
3. Valve safety covers and the labels showing contents must be in place.
J. HYDROSTATIC TESTING
Hydrostatic pressure tests are performed on most cylinders every five years to
determine their fitness for further use. At this time, new test dates are stamped into the
shoulder of the cylinder. Present regulations permit visual tests in lieu of hydrostatic
tests for low-pressure cylinders in certain gases free of corrosive agents. Special permits
allow for hydrostatic pressure tests at ten-year intervals for cylinders in high-pressure
service for certain gases (cylinders that require hydrostatic testing every 10 years have a
five-pointed star stamped next to the hydrostatic test date). Original inspector’s insignia
for conducting hydrostatic and other required tests to approve the cylinder under
Department of Transportation specifications must be on the cylinder.
K. LECTURE BOTTLES
In addition to standard precautions, the following shall apply to work with lecture bottles
in the laboratory:
· Lecture bottles shall be stored where the temperature does not exceed 50C. Unlike larger cylinders, lecture bottles do not have pressure-relief devices to prevent rupturing.
· If labels and valve tags do not agree, or if there is any question as to the contents of a lecture bottle, return it to the supplier.
· Lecture bottles should be purchased from suppliers who will accept the return of empty or partially empty bottles or leased from a supplier who offers a leasing option for lecture bottles. Contact EHS for names of suppliers who offer leasing options for lecture bottles.
L. ACETYLENE
The following special rules apply to work with cylinders of acetylene:
· Acetylene cylinders should be stored in an upright position if possible. If a cylinder of acetylene has been stored in a non-upright position, do not use it until it has sat upright for at least 30 minutes.
· Acetylene cylinders should be tightly secured with straps or chains and stored where they are unlikely to be struck.
· When connecting an acetylene cylinder, be sure to use a flash arrester at the outlet of the cylinder and the correct kind of tubing to transfer the gas. Some tubing materials, such as copper and lead solder, form explosive acetylides.
· Never exceed the pressure limit indicated by the warning red line of an acetylene pressure gauge.
· Never under any circumstances attempt to transfer acetylene from one cylinder to another, to refill acetylene cylinders, or to mix any other gas with acetylene in a cylinder.
· Do not store acetylene cylinders near oxygen cylinders.
M. Cryogens
Special Precautions for Working with Cryogens: Some of the hazards associated with
cryogens (fluids used to maintain extremely low temperatures) are fire, pressure,
embrittlement of materials, and skin or eye burns upon contact with the liquid. Cryogens
can condense nearly pure liquid oxygen from the air, creating a severe fire risk. A
pressure hazard exists because of the large expansion ratio from liquid to gas, causing
pressure build up in containers. Many materials become brittle at extreme low
temperatures. Brief contact with materials at extreme low temperatures can cause burns
similar to thermal burns. Carefully observe all special precautions.
1 Equipment should be kept clean, especially when working with liquid or gaseous
oxygen.
2. Mixtures of gases or fluids should be strictly controlled to prevent formation of
flammable or explosive mixtures.
3. For flammable cryogens the precautions provided in the "Flammable/Combustible
Materials" section of this booklet should be used.
4. Always wear goggles when handling cryogens. If there is a splash or spray hazard, a
face shield over the goggles, an impervious apron or coat, cuffless trousers, and
fully-covering, non-lacing shoes should be worn. Watches, rings, and other jewelry
should not be worn. Gloves should be impervious and sufficiently large to be readily
thrown off should a cryogen be spilled. Cryo-gloves or pot holders should also be
used. Respirators may be required if the cryogen is toxic and sufficient local exhaust
ventilation is not available. Contact EHS for exposure monitoring.
5. Containers and systems containing cryogens should have pressure relief mechanisms.
6. Containers and systems should be capable of withstanding extreme cold without
becoming brittle. Glass containers should be taped solidly around the outside or
encased in plastic mesh.
7. Funnels should not be used for pouring liquid nitrogen or any other cryogen.
8. Large mobile Dewars or LN2 refrigerators (or the trolleys carrying these) used for
transporting cryogens within a building or between buildings should be equipped
with a braking mechanism.
9. Large mobile Dewars at risk for tipping should be transported on appropriate carts.
Wheeled trolleys may not be used if the vessel must pass over elevator thresholds or
other slots/crevasses wider than 25% of the wheel width.
10. Dispensing stations designed to allow research staff to fill smaller vessels from a
larger self-pressurizing Dewar must be located in non-public areas, and should be
posted with standard operating procedures.
11. Smaller vessels of liquid nitrogen or other cryogens transported by hand within or
between buildings must have a handle or bail, and must be covered.
N. COMPRESSED AIR
Compressed air is used for many purposes at the University and the following safety
guidelines should be observed:
1.Air lines must be reduced in pressure so as to not exceed 30 psi at the nozzle.
2.Inspect lines regularly.
3.Portable air lines must be stored so they do not hang or extend into machine work areas or
traffic patterns. Suitable spring hangers, hose reels, sway bracing, vibration dampers, etc.
must be provided.
4.A pressure gauge or a valved connection for a pressure gauge should be located at the
outlet of each pressure- reducing valve.
5.Air receivers must be installed so that all drains, handholes, and manholes therein are easily
accessible. Air receivers should be supported with sufficient clearance to permit a complete
external inspection and to avoid corrosion of external surfaces. Under no circumstances
shall an air receiver be buried underground or located in an inaccessible place. The receiver
should be located as close to the compressor or aftercooler as possible in order to keep the
discharge pipe short.
6. A drain pipe and valve should be installed at the lowest point of every air receiver to
provide for the removal of accumulated oil and water. Adequate automatic traps may be
installed in addition to drain valves. The receiver should be completely drained frequently
and at such intervals as to prevent the accumulation of excessive amounts of liquid in the
receiver.
7 .Every air receiver should be equipped with a visible pressure gauge with one or more
spring-loaded safety valves. The total relieving capacity of the safety valve should be such
as to prevent pressure in the receiver from exceeding the maximum allowable working
pressure of the receiver by more than 10%.
8. No valve of any type is to be placed between the air receiver and its safety valve or valves.
9. Safety appliances, such as safety valves, indicating devices and controlling devices, are to
be constructed,
located, and installed so that they cannot be rendered inoperative by any means.
10.All safety valves are to be tested frequently and at regular intervals to determine whether
they are in good operating condition.
11.Extreme care should be taken in cleaning the worksite with compressed air. Small particles
can be given sufficient velocity to cause severe eye damage. Adequate eye protection such
as safety goggles must be worn by all persons engaged in cleaning with compressed air.
Use of compressed air to "blow down" or clean oneself off at anytime is
prohibited.
MAXIMUM SIZE AND QUANTITY LIMITATIONS FOR COMPRESSED OR LIQUIFIED GAS CYLINDERS IN LABORATORIES
|
|
Flammable Gases and Oxygen |
Liquified Flammable Gases |
Gases with High Health Hazard Rating |
|
Maximum cylinder size (approximate dimensions in inches) |
10 x 50 |
9 x 30 |
4 x 15 |
|
Maximum number of cylinders per 500 square feet or less of floor space in nonsprinklered areas |
3 |
2 |
3** |
|
Maximum number of cylinders per 500 square feet or less of floor space in sprinklered areas |
6* |
3 |
3** |
|
*In instructional laboratory work areas, the total number of cylinders shall be reduced to 3 maximum-sized cylinders or ten approximately 2” x 13” cylinders (lecture bottles) are allowed. In other than instructional laboratories, 25 lecture bottles are permitted. |
|||
|
**Cylinders of all toxic gases shall be kept in a continuously mechanically ventilated hood or other continuously mechanically vented enclosure, with no more than 3 cylinders per enclosure.
|
|||
Reference: NFPA 45, Fire Protection for Laboratories Using Chemicals, National Fire Protection Association, 1991.
VI. Employee Exposure
Criteria used to determine and implement control measures to reduce employee exposure to hazardous chemicals include engineering controls, the use of personal protective equipment, and proper chemical and personnel hygiene practices and procedures. Particular attention shall be given to the selection of control measures for chemicals that are known to be extremely hazardous.
The American Conference of Governmental Industrial Hygienists (ACGIH) produces annual lists of Threshold Limit Values (TLV’s) and Short Term Exposure Limits (STELS) for common chemicals used in laboratories. These values are guides, not legal standards (but can be enforced by OSHA under the General Duty Clause as consenus standards, especially if there is no corresponding PEL. They are defined as follows:
TLV-Time-weighted average concentration for a normal 8-hour workday to which nearly all workers may be repeatedly exposed without adverse effect.
STEL-Maximum concentration to which workers can be exposed for periods up to 15 min. Such exposures should be limited to no more than four per day with periods of at least 60 min each between exposures; the total time-weighted exposure per day should not exceed the TLV value.
Most of the 1968 TLVs were adopted by OSHA in 1972 as legal Permissible Exposure Levels (PELs). The basis for selection of the TLVs appears to be more secure than the justification for the STELS. The TLVs provide a useful estimate of how much ventilation may be needed in laboratories where the occupants typically spend most of their working time.
However, because of the many factors influencing toxicity, each situation should be evaluated individually and the TLVs used as guidelines rather than as fine lines between safe and dangerous concentrations.
The best way to avoid exposure to toxic vapors, mists, gases, and dusts is to prevent the escape of such materials into the working atmosphere and to ensure adequate ventilation by the use of exhaust hoods and other local ventilation.
Every laboratory worker should observe the following rules:
1. Know the safety rules and procedures that apply to the work that is being done. Determine the potential hazards (e.g., physical, chemical, biological) and appropriate safety precautions before beginning any new operation.
2. Know the location of and how to use the emergency equipment in your area, as well as how to obtain additional help in an emergency, and be familiar with emergency procedures.
3. Know the types of protective equipment available and use the proper type for each job.
4. Be alert to unsafe conditions and actions and call attention to them so that corrections can be made as soon as possible. Someone else’s accident can be as dangerous to you as any you might have.
5. Do not consume or store food or beverages or smoke in areas where chemicals are being used or stored.
A. General Requirements
1. Employee Exposure Determination
a. Initial Monitoring
The Department of Environmental Health and Safety will measure an employee’s exposure to any substance regulated by a standard which requires monitoring if there is reason to believe that exposure levels for that substance routinely exceed the action level (or in the absence of an action level, the permissible exposure level).
b. Periodic Monitoring
If the initial monitoring discloses employee exposure over the action level (or in the absence of and action level, the PEL), the exposure monitoring provisions of the relevant standard will be followed.
c. Termination of Monitoring
Monitoring may be terminated in accordance with the relevant standard.
d. Employee Notification of Monitoring
A copy of the results of such monitoring will be sent to the employee or employees involved (or posted in an appropriate location near the area tested) within 15 days of receipt of the test results. The Office of Environmental Health and Safety will maintain an official record of the results.
2. Chemical Spills or Leaks
In the case of a spill, if the spill is a small amount (less than one liter) inside a fume, the spill should be cleaned up immediately using the proper personal protective equipment (PPE required for cleanup) and appropriate absorbent material (Consult the material safety sheet for information on spill cleanup). If the spill occurs outside the hood, amounts of one liter or less of low toxicity materials may be cleaned up by trained laboratory personnel only if the proper cleanup materials and personal protective equipment required for cleanup are used. If Chemicals of high toxicity are spilled outside chemical fume hoods, alert other personnel in the area, evacuate the area, close the laboratory door and call 911. (Refer to Appendix D for further information on spill cleanup and response)
3. Odor Detection
Detection of odors is not a reliable means of judging the hazard of an exposure. There are several variables in the odor threshold, and variables in human detection of odor.
There are some materials which have a strong or easily-detected odor at concentrations which are far below any level at which health hazards are likely to occur. For example, mercaptans and ethyl ether have such low odor thresholds that they give an early warning of their presence.
Other toxic materials are odorless or cannot be detected at concentrations below the permissible exposure limits. The ability to perceive odor varies among individuals and not everyone can smell odors of certain chemicals which may be extremely toxic, such as hydrogen cyanide or hydrogen sulfide. Other individuals exposed to odorous chemicals day to day may eventually experience a diminished or complete inability to detect certain odors.
The ability to perceive odor may also vary depending on interfering odors and with time and concentration. After a short exposure to some strong chemical odors (e.g., phosgene, formaldehyde, and hydrogen sulfide), olfactory fatigue may occur so that a person is no longer able to smell the odor. If olfactory fatigue does occur, a person may be in great danger because he thinks the exposure no longer exists.
As an example, hydrogen sulfide has the strong odor of rotten eggs and can be detected at concentrations as low as 0.025 parts per million (ppm). It is distinct at 0.3ppm, offensive and moderately intense at 3-5ppm and strong but not intolerable at 20-30ppm. (The maximum concentration allowable for a prolonged or work-day exposure is 20ppm).
4. Signs and Symptoms of Overexposure
While your senses may not give you precise information, there is a lot you and your co-workers can find out by perceptive observation not only of the working conditions, but of your own sensations.
There are two classes of adverse health effects you may be able to perceive:
1. Signs - evidence which is observable by others
2. Symptoms - evidence which is subjective and not observable by others
Signs of Inhalation Exposure
If you suddenly begin sneezing or coughing, your eyes begin to water, or your gait becomes staggered, these are signs observable by yourself (as well as by others) that you could possibly be exposed to irritating gases or vapors. Changes in breathing rate could be another sign of exposure.
Symptoms of Inhalation Exposure
Symptoms of exposure to irritating gases or vapors include: headache, irritation of eyes, nose, and throat; increased secretion of mucous in your nose and throat; and other subjective evidence.
Signs of Skin Contact
In case of skin exposure to chemicals, you may see signs of redness (erythema), swelling (edema), or dry whitened skin. You may experience symptoms of irritation and itching.
The skin on your hands may become dry and whitened if you wash residues off your hands with organic solvents. This results from removing some of the lipids from the surface of your skin. Repeated or prolonged contact with solvents is likely to lead to cracked and red skin or dermatitis, which can be a lifelong problem.
Other Signs and Symptoms of Chemical Overexposure
Potentially hazardous exposures may be recognizable from fairly obvious signs or symptoms, but such evidence may be overlooked or ignored if you are not prepared to observe it. In addition to some easily recognizable signs, there can be subtle effects that need to be recognized. Here is a list of some of the subtle signs and symptoms which can be caused by chemical exposures (or which could also be caused by other factors, including illness):
· Changes in normal behavior patterns
· Periods of dizziness
· Muscle spasms
· Irritability
Some of these signs and symptoms may occur in a short time, while others may not be noticed unless the exposure is several days in length.
Be prepared to get out of the area if symptoms appear suddenly. If the symptoms disappear or alleviate quickly once you are out of the area, alert you supervisor and others in the area.
If care is taken to ensure that (1) the ventilation system (including the hood) is
performing and being used properly (2) the laboratory workers are using proper
protective clothing to avoid skin contact and (3) the laboratory workers are
following good hygiene and laboratory safety practices, then even highly toxic
materials can be handled without undue risk.
B. Laboratory Specific Criteria
Place laboratory specific criteria for the selection of personal protective equipment for specific chemical procedures, here. Contact EHS for information and assistance.
VII. MEDICAL CONSULTATION AND EVALUATION
A. General Requirements
The University’s provisions for medical consultation and medical examinations shall be in accordance with paragraph (g) of the OSHA standard "OCCUPATIONAL EXPOSURES TO HAZARDOUS CHEMICALS IN LABORATORIES", reproduced below.
(g) Medical consultation and medical examinations.
(1) The employer shall provide all employees who work with hazardous chemicals an opportunity to receive medical attention, including any follow-up examinations which the examining physician determines to be necessary, under the following circumstances:
(i) Whenever an employee develops signs or symptoms associated with a hazardous chemical to which the employee may have been exposed in the laboratory, the employee shall be provided an opportunity to receive an appropriate medical examination.
(ii) Where exposure monitoring reveals an exposure level routinely above the action level (or in the absence of an action level, the PEL) for an OSHA regulated substance for which there are exposure monitoring and medical surveillance requirements, medical surveillance shall be established for the affected employee as prescribed by the particular standard. (See Appendix for a list of regulated or listed carcinogens)
(iii) Whenever an event takes place in the work area such as a spill, leak, explosion or other occurrence resulting in the likelihood of a hazardous exposure, the affected employee shall be provided an opportunity for a medical consultation. Such consultation shall be for the purpose of determining the need for a medical examination.
(2) All medical examinations and consultations shall be performed by or under the direct supervision of a licensed physician and shall be provided without cost to the employee without loss of pay and at a reasonable time and place.
(3) Information provided to the physician. The employer shall provide the following information to the physician:
(i) The identity of the hazardous chemical(s) to which the employee may have been exposed;
A description of the conditions under which the exposure occurred including quantitative exposure data, if available.
(ii) A description of the signs and symptoms of exposure that the employee is experiencing, if any.
(4) Physician's written opinion.
(5) For examination or consultation required under this standard, the employer shall obtain a written opinion from the examining physician which shall include the following:
(A) Any recommendation for further medical follow-up;
(B) The results of the medical examination and any associated tests;
(C) Any medical condition which may be revealed in the course of the examination which may place the employee at increased risk as a result of exposure to a hazardous chemical found in the workplace; and,
(D) A statement that the employee has been informed by the physician of the results of the consultation or medical examination and any medical condition that may require further examination or treatment.
(iii) The written opinion shall not reveal specific findings of diagnoses unrelated to occupational exposure.
The department head or his/her designee shall ensure that the following information is provided to the physician:
1. The identity of the chemical involved in the exposure