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.