Reusable grocery totes are good for the environment, but they may be bad for your health if you don't wash them regularly. The bags can harbor harmful bacteria from raw meats and unclean objects that can contaminate food and cause food poisoning.
According to an Academy of Nutrition and Dietetics survey, only 15 percent of Americans regularly wash their bags. The Academy recommends frequently washing the totes in the washing machine or by hand in hot, soapy water and disinfecting counters and other surfaces where you place them.
And be careful to store them in a clean, dry placenot in your car trunk.
Source: Academy of Nutrition and Dietetics news release 4/3/12; Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50