Office of Research

Appendix D


Many situations exist in which a person entering an area needs to be made aware that a hazard exists in the area or needs to know of restrictions placed on persons entering the area. In addition, there are signs which are intended to provide information to individuals in an emergency. There are literally hundreds of specialized safety signs and symbols which can be purchased for the laboratory. 


An “Emergency Information” sign shall be posted outside all laboratories, either on the outside of the door or on the wall beside the door.(It is also a good idea to post one of these signs inside the laboratory, near the telephone, if there is a telephone in the lab.) This sign must provide telephone numbers for emergency personnel, telephone numbers of responsible faculty and staff, information on specific hazards in the laboratory, special precautions. NO EATING, DRINKING OR SMOKING should also be included on this sign. In many cases, signs relating to specific hazards are mandated by regulatory requirements, while in other cases they represent good safety practices. In most cases, the hazard signs will be prefaced by a risk descriptor, defining the level of risk represented in the specific instance. The three cautionary words in normal use, in decreasing order of risk are DANGER, WARNING, and CAUTION. A blank form to be used for this purpose is located at the end of this Appendix.

Standard signs and symbols have been established for a number of special situations, such as radioactivity hazards, biological hazards, fire hazards, and laser operations.


Building evacuation plans should include evacuation routes, emergency telephone numbers, location of fire alarms, and area or areas designated for assembly after evacuating. These plans should be placed in corridors on all floors of every building. The evacuation plan should enable a person unfamiliar with the building to escape in an emergency.


Other signs should be posted to show the location of safety showers, eyewash stations, first aid, exits, fire extinguishers, and fire alarms. Extinguishers should be labeled to show the type of fire for which they are intended. Signs used to indicate location of safety showers, eyewash stations, and first aid supplies are green and white. Signs used to indicate location of fire extinguishers, fire alarms, and exits are red and white.



Waste containers should be labeled for the type of waste that can be safely deposited (e.g., biohazardous, broken glass, sharps, etc.).



Chemical storage rooms should be posted (e.g., DANGER, CHEMICAL STORAGE, FLAMMABLE, NO SMOKING, etc.). Chemical storage cabinets should be posted with appropriate warnings (e.g., FLAMMABLE, CORROSIVE, POISON, CARCINOGEN, etc.)



Refrigerators, freezers, and microwave ovens in laboratories should be posted (NO FOOD OR BEVERAGE TO BE USED FOR HUMAN CONSUMPTION ALLOWED IN THIS…); refrigerators and freezers should also be posted (NO FLAMMABLES), unless the refrigerator is designed for the storage of flammables. Drying ovens, unless designed for handling volatile and flammable materials should be posted accordingly.

Other laboratory equipment should be posted to indicate hazards (e.g., HOT, FINGER/HAND HAZARD, ALWAYS USE SHIELDING, etc.).



Examples of other important types of signs and a brief description of the types of applications for which they would be needed:

1.    AREA UNSAFE FOR OCCUPANCY - This is used to indicate a contaminated area or an area otherwise rendered unsafe, temporarily or otherwise, for normal use.

2.    ASBESTOS - Asbestos is still used in a number of products employed in laboratories. If there is the potential while using these products that asbestos fibers may become airborne, the area needs to be marked with a sign:





Note that a sign such as this does not say that there are asbestos fibers in the air. The sign is intended to alert people that their actions could result in the generation of airborne asbestos fibers. If there is a risk that airborne asbestos fibers may be present, the Asbestos Shop of University Facilities and Maintenance needs to be notified.


3.    BIOLOGICAL HAZARD -The sign will be accompanied by the universal biohazard symbol indicating that an agent which may prove infectious to human beings is present within the area.

4.    CARCINOGENIC HAZARD - The Laboratory Standard requires that areas in which carcinogenic agents are in use be designated as such. This can be done with a sign such as:







Where the agent might be unusually dangerous, the agent would be specified and any special protective measures needed would be appended.


5.    SAFETY GLASSES REQUIRED - It is recommended that this sign be used at the entrances to all active laboratories where chemicals are stored or used.

6.    CRYOGENIC LIQUIDS - All containers which contain cryogenic liquids, most commonly liquid nitrogen, but also other gases maintained at very low temperatures should be prominently labeled.

     The container, usually a large flask with walls separated by a vacuum called a dewar, should also be labeled with the cautionary information:





7.    HIGH VOLTAGE DANGER - Spaces which contain accessible high voltage panels, such as switch rooms and electrical closets, should be locked and provided with these signs to warn persons lacking training and experience in working with high voltage circuits not to enter. Equipment containing high voltage circuits should also bear this warning label.

8.    HYDROGEN-FLAMMABLE GAS, NO SMOKING OR OPEN FLAMES- This sign must be posted in all areas where hydrogen is used or stored.

9.    INTERLOCKS ON - Equipment with internal hazards, such as X-ray diffraction cameras, or areas in which the space is rendered unsafe to enter by the presence of a hazard, are often provided with a fail safe circuit, or interlock, which will turn off the equipment creating the problem if the circuit is broken. The sign provides a warning that the interlock is on to prevent access to the hazard.

10.    LASERS - Labeling of lasers should follow 21CFR1040, the Federal Laser Product Performance Standard. The spaces in which lasers are located should also have a similar warning at the entrance. The label will depend upon the class of laser involved. All of the labels will include a stylized sunburst symbol, with a tail extending to the left. The signal work CAUTION is to be used with Class II and IIIA laser systems while the signal word DANGER is to be used for all Class IIIB and Class IV systems. (Contact the Radiation Safety Officer for further information)

11.    MACHINE GUARDS IN PLACE - OSHA requires that many machines, such as vacuum pumps or shop equipment, be provided with guards over the moving parts. Signs should be posted near these machines to remind employees not to use the equipment if the guards are not in place.

12.    MICROWAVES - This sign must be posted in any area where it is possible to exceed the current occupationally legal limit of exposure to microwave electromagnetic radiation.

13.    NO SMOKING - This sign should be posted wherever flammables are in use; where there is a risk of explosion due to the presence of explosives or from gases, vapors, or dusts; and where toxic materials are in use.

14.    RADIATION AREA - Areas where the radiation exceeds a level established by the NRC must be posted. If the level exceeds a higher level set by the NRC, the area must be posted with a HIGH RADIATION AREA sign. Most of these areas will be within an area posted with a RESTRICTED AREA-AUTHORIZED ADMISSION ONLY sign. Areas where radioactive materials are stored should be posted with a CAUTION-RADIOACTIVE MATERIALS sign.

15.    ULTRAVIOLET LIGHT, EYE PROTECTION REQUIRED - This sign should be posted wherever there is risk of eye injury due to ultraviolet light emission.



All containers of chemicals in the laboratory shall bear labels indicating contents and associated hazards. The hazard warnings can be words, pictures, or symbols which provide an immediate understanding of the primary health and/or physical hazard(s) of the material. Many manufacturers have designed unique labeling systems to provide the user with valuable information about their products.

The following provides information about some labeling systems that are widely used by chemical manufacturers.


National Fire Protection Association 704, Standard for the Identification of Fire Hazards of Materials, is one of the most widely used marking systems. Although there is no University requirement that labeling must comply with this system, it is helpful to be familiar with these labels as they are so pervasive. Be prepared to recognize these markings on containers received from vendors. Be aware that this labeling system does not in itself meet the requirements of the Hazard Communication Standard. 

The system was originally devised for industry to use on such facilities as storage tanks or buildings so that firefighters could assess the hazard from a safe distance and better evaluate what fire-fighting techniques to employ. The system can also be useful in situations other than fires when used on container labels or room doors so that a person working in the room or area can quickly determine the degree of hazard of a particular chemical. Several kinds of kits with pressure-sensitive diamonds and separate numbers in several sizes can be purchased from safety supply distributors.

The system does not provide any detailed hazard information and does not supersede the need for posting the other required information (such as the name of the chemical and the name of the manufacturer) on a portable container label. The diamond-shaped label shown in the following information identifies three categories of hazards in three squares of different colors. The blue square at the left indicates health hazard, the red square at the top indicates flammability, and the yellow square at the right indicates reactivity.

The degree of severity under fire conditions is indicated numerically by five divisions ranging from 0 to 4, with 0 indicating no hazard and 4 indicating severe hazard. Any special hazard, such as unusual reactivity with water, is indicated in a white square at the bottom of the diamond. A more detailed definition of each numerical category appears on at the end of this appendix.


The chemical manufacturer/distributor is required to provide labels on all hazardous chemicals shipped. These labels should include a product identifier, signal word, hazard statement(s), pictogram(s), precautionary statement(s), and the name, address, and telephone number of the manufacturer, importer, or other responsible party. Portable containers of working solutions must also be labeled appropriately. Labels must be legible and must be prominently displayed on the container. Labels on incoming containers must not be defaced or removed until the container is empty. Once the container is empty, the guidelines in the University Hazardous Waste Management Manual should be followed for container disposal. Whenever chemicals are transferred into another container, the container must be labeled with the full chemical name, appropriate hazard warnings, and the manufacturer’s name, address and telephone number. The date of transfer, name or initials of the person making the transfer, and additional information about the possible health effects should also be included. In the event that labels must be created, the labels must be durable, legible, and must be firmly affixed to the container(s). Labels should be replaced whenever they fade, peel, or otherwise deteriorate so as to become difficult to read. All chemicals should be dated upon receipt. No chemical should ever be used without completely reading the label. Contents of all vessels, pipelines, storage tanks, etc. must be adequately labeled. Products that are synthesized at Clemson and distributed outside of the University proper must be labeled in accordance with OSHA’s Hazard Communication Standard, if they contain hazardous chemicals in concentrations greater than one percent (or 0.1% for carcinogens). If shipping hazardous chemicals from Clemson University, labeling must comply with the 2012 HCS , must be shipped with a Safety Data Sheet, and the personnel shipping the material must have completed the appropriate training.

  • Signal Words are used to indicate the relative level of severity of a hazard.  It alerts the user to a potential hazard.  There are only two words allowed: “Danger” and “Warning”.  Danger is used for more severe hazards.  Warning is used for less severe hazards.  Only one signal word will appear on the chemical label.  Not all labels will have a signal word; some chemicals are not hazardous enough to require that a signal word appear on the label.
  • Hazard Statements are assigned to a hazard class and category that describes the nature of the hazard based on the chemical hazard classification.  For example a hazard statement may be “fatal if swallowed” or “toxic in contact with skin.”
  • Precautionary Statements describe the recommended measures to be taken to minimize or prevent adverse effects from exposure to a hazardous chemical or improper storage or handling of a hazardous chemical.  Some examples of precautionary statements are “if swallowed call poison control” or “store away from other materials.”
  • Pictograms are intended to convey specific information about the hazards of a chemical.  Pictograms will have a black picture atop a white background within a red square frame set on a point.  There are nine pictograms under the 2012 HCS, but only eight are enforced by OSHA.  The environmental pictogram for aquatic toxicity is not mandatory because OSHA does not have jurisdictional authority.