According to a joint food safety research report issued by researchers at the University of Arizona and Loma Linda University, reusable grocery bags can serve as a breeding ground for dangerous foodborne bacteria and pose a serious risk to public health.

The researchers randomly tested reusable grocery bags carried by shoppers in Los Angeles, San Francisco, and Tucson. Researchers also found consumers were almost completely unaware of the need to regularly wash their bags.

“Our findings suggest a serious threat to public health, especially from coliform bacteria including E. coli, which were detected in half the bags sampled,” said Charles Gerba, Ph.D., a University of Arizona environmental microbiology professor and co-author of the study. “Furthermore, consumers are alarmingly unaware of these risks and the critical need to sanitize their bags after every use.”

reusable-bag.jpgGerber said the bacteria levels found in reusable bags were significant enough to cause a wide range of serious health problems and even lead to death. This is a particular danger for young children who are especially vulnerable to foodborne illnesses.

The study found that people were not aware of the potential risks.  A full 97 percent of those interviewed have never washed or bleached their bags.  Gerber said that thorough washing kills nearly all bacteria that accumulate in reusable bags.

The report comes at a time when some members of the California State Legislature, through Assembly Bill 1998, are seeking to promote increased consumer use of reusable bags by banning plastic bags from California stores.

“If this is the direction California wants to go, our policymakers should be prepared to address the ramifications for public health,” said co-author Ryan Sinclair, Ph.D., a professor at Loma Linda University’s School of Public Health.

The report noted that “a sudden or significant increase in use of reusable bags without a major public education campaign on how to reduce cross contamination would create the risk of significant adverse public health impact.”

Sinclair noted that contamination rates appeared to be higher in Los Angeles than the other two locations. He believes this is likely due to that region’s weather being more conducive to growth of bacteria in reusable bags.

The report, “Assessment of the Potential for Cross Contamination of Food Products by Reusable Shopping Bags,” offered the following policy recommendations for lawmakers, as well as tips for consumers who use reusable grocery bags including:

1.  When using reusable bags, consumers should be careful to separate raw foods from other food products,

2.  Consumers should not use reusable food bags for such other purposes as carrying books or gym clothes, and

3.  Consumers should not store reusable bags in the trunks of cars because the higher temperature promotes growth of bacteria.

Haggen grocery stores have introduced an antibacterial polypropylene reusable bag that helps prevent the spread of bacteria that can cause foodborne illness.

The antibacterial bags at Haggen and TOP Food stores are the first in the world that are treated with AP-360, an antimicrobial product that controls harmful and odor-causing bacteria (MRSA), mold, mildew, and fungus. It is produced from natural resources that are abundantly renewable. Chitin, the active substance, is derived from the shells of crabs and contains unique antimicrobial properties.

“We know some customers have wanted to embrace the environmental benefits of reusable bags but have had food safety concerns,” said Becky Skaggs, spokesperson for Haggen and TOP Food stores. “These antibacterial reusable bags help prevent the spread of E. coli, Salmonella and other bacteria that can cause foodborne illnesses, even after repeated washings.”

Haggen and TOP Food stores contracted with Proforma Mountainview Printing of Lynden, Washington, which used chitin in developing the antibacterial reusable bags.

The bags are $1.99 a piece and are safe to use by everyone, including those who are allergic to shellfish, according to the Bellingham Herald.

A partial list of bacteria and fungi that are controlled by AP-360 can be found online.

  • Do you eat your reusable bags? No… So stop fretting.

  • Al

    This is a reasonable concern, but since you can wash reusable bags, doesn’t seem to be that big of a deal to me……the benefits for the environment resulting from large-scale adoption of reusable bags is worth it. Just like we have to wash our dishes and tableware, table cloths, and bathroom towels and even our hands, we also have to wash our reusable grocery bags. It is a good reminder, though, to always keep sanitation and safety on our minds. The “not keeping in the trunk” is something I didn’t know and will bear in mind. Thanks

  • Josh

    One easy solution is to just use and recycle plastic bags. Almost every store has a bring back recycling program now.

  • Steve

    In reply to Josh: Most stores that accept your used plastic bags for “recycling” actually end up sending them to a company that makes plastic lumber – – not new bags. Don’t get me wrong, there’s merit to plastic lumber but there are also plenty of other sources for raw material for plastic lumber. In this case, I’d call it “downcycling” rather than “recycling” since a plastic bag seems to me to have more value than a plastic board. And, in the end, the plastic board will likely be landfilled at the end of it’s useful life.
    Recycling that plastic bag is better than tossing it to the breeze…but don’t let that take away all of your consumer guilt 🙂

  • jessica

    Is it “Gerber” the food company or “Gerba”?

  • amy

    Just wash them once in a while and always use plastic bags for meat. (I don’t buy much meat anyway)

  • Jim K

    As the reusable grocery bag market becomes bigger…and it will with all the new legislation, I am happy that there is a bag that controls bacteria as a feature. This AP-360 is great and seems to be renewable and safe? I love my shirts and socks that have this technology, so why not something that I put my food into. I do clean my bags, sometimes, but most the time…and separate meats and produce…the odd thing is when they pack the bags at the store, some of the packers do not know how to separate the foods? Education is the best…separate foods, and use a antibacterial bag – but don’t forget to clean it out!

  • Approx. 380 million dollars is spent by consumers a year in the stated of California on the “convenience” of using the single-use plastic bags offered by grocery chains today, with another 25 mil spent by taxpayers to cleanup their mess. The reusable grocery bag concept is an attempt to do more than clean up the environment, it is clearly an attempt by lobbyist and politicians to “pass the buck” onto the consumer once again. I’m not saying we don’t need a solution, but just as in so many things, people want to leap before they look! If the general populus in Calif. all chose the aforementioned AP-360 treated bags, that mere 380 mil would be increased 100 times over (cost of plastic bag ~ $0.02 vs. $2.00) OUCH! Do you think that our overall cost of groceries would be reduced? I wish! We could only hope that if we as consumers could afford such a thing, then we could afford to do proper R and D and find the correct solution. This is a much bigger issue than any of us realize!

  • arlene B

    I may be crazy but how exactly do you wash the grocery bags? I plastic ones you can sponge out but the other ones that most stores have can you put them in the washing machine? I really don’t know what they are made of. Can you put them in the dryer?

  • Sheryl

    In the news in the recent months, statements were made that these reusable bags are made with lead and not to use them. I have several, and wanted to know if this statement is true. I am looking to you for an answer, if I should keep them and use them, or toss because of the lead.

  • Jo

    no matter what we do after we are told it’s for the best, you’re still wrong. so do what you think is right not what someone tells is the best way to do it.