Unwashed Reusable Grocery Bags Breed Bacteria

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Pam Schmutz, Home & Garden Information Center
Angela Fraser, Extension Food Safety Specialist

Cloth shopping bags may be good for the environment, but are they good for your health? Research shows that they need to be cleaned regularly to keep them from becoming breeding grounds for germs. Researchers at the University of Arizona and Loma Linda University in California tested reusable bags from 84 people entering grocery stores. While they did not find any harmful bacteria, such as Salmonella or Listeria, they did find large numbers of bacteria commonly on surfaces and in the environment.

So what does this mean? Reusable grocery bags are safe—but you do need to keep them clean. Interestingly, only 3% of 84 people who had their bags tested reported ever cleaning their reusable bags! Hand or machine wash them in hot, soapy water at least once a week, and always wash after a spill. After washing, machine dry or turn inside out and hang dry. Doing so will reduce the number of bacteria inside and outside the bag by more than 99.9%.

The greatest danger is from meat, fish or poultry juices contaminating the bag or other foods with harmful bacteria that can make you sick. Packages of raw foods can have bacteria even on the outside. Always remember to put packages of meat, fish or poultry in a disposable bag to catch leaks. The disposable bag can then be put in your reusable bag.

Another problem noted was that 30% of the 84 people used their bags to carry non-food items, such as books and clothes. Only use your reusable grocery bag to hold food. If you need to carry books or gym clothes or other non-food items, use a different bag.

Follow these other tips to keep your bags ready for use:

  • Put unpackaged produce in disposable bags. Not only can bacteria from the produce contaminate other foods, but the produce can pick up bacteria from the bag itself. If the produce is not cooked, the bacteria will survive.
  • Never store unwashed reusable bags in a hot car where bacteria can thrive. This is a real concern in hot, humid climates like South Carolina.

Reusable grocery bags are good for the environment, but keep them clean so they will be good for your health too!

Sources:

  1. Gerba, Charles P., David Williams and Ryan G. Sinclair. June 9, 2010. Assessment of the Potential for Cross Contamination of Food Products by Reusable Shopping Bags. http://www.llu.edu/assets/publichealth/documents/grocery-bags-bacteria.pdf
  2. Consumer Reports. July 22, 2010. Can Reusable Grocery Bags Make You Sick, Or Is That Just Baloney? http://blogs.consumerreports.org/safety/2010/07/can-reusable-grocery-bags-make-you-sick-or-is-that-just-baloney.html

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