If you’ve made the switch to reusable shopping bags to make your lifestyle more environmentally responsible, how often do you toss them in the washing machine? Chances are, not regularly.
A study from the University of Arizona and Loma Linda University in California found that most people who bring their own bags to the grocery store don’t wash or clean them regularly – and the researchers also discovered a large number of bacteria present in the reusable bags. So should you be concerned about microorganisms breeding in your reusable bags?
Of the 84 reusable shopping bags collected from cities in California and Arizona, slightly more than half of the bags contained coliform bacteria, which indicates contamination by raw meats or other uncooked food products, the report states. The researchers detected E. coli bacteria in 12 percent of the bags.
Only 3 percent of the shoppers surveyed reported ever washing or cleaning their bags.
But lest you get nervous about using your reusable bags, the research, which was funded by the American Chemistry Council, determined that simple hand or machine washing eliminated bag bacteria by nearly 100 percent. In addition to regularly washing your reusable bags, the study suggests not using the same bags you use to carry groceries for other germ-laden activities, such as toting dirty clothes to the laundromat.
Dr. Charles Gerba, who co-authored the report, also recommends keeping raw meat in a separate bag that will not be used to carry vegetables or fruit that will be eaten raw.
But Andy Keller, president of reusable bag company ChicoBag, is concerned that this study unfairly singles out reusable bags as a source of bacteria and, because it was funded by a trade group that represents single-use plastic bag manufacturers, is intended to drive consumers away from reusable bags.
“Our world is covered in bacteria, and not all bacteria growth is dangerous or should be discouraged,” Keller says.
According to the EPA, many strains of coliform bacteria – even E. coli – do not pose a human health risk.
“Reusable bags are no different than any other consumer product, and good hygiene is a matter of common sense,” Keller says.
Keller thinks that makers of single-use plastic bags have been using the study’s findings to promote their product’s superiority, overstating the threat of bacteria found in reusable bags and presenting the washing of reusable bags as a burden on busy individuals.
“The apparent motivation behind the study [is to] create fear, uncertainty and doubt about reusable bags and position single-use, disposable bags as the safe alternative,” he says.
“Single-use bags have a place in our society,” he continues. “But we use 102 billion single-use bags in the U.S. annually – and half of those bags, we don’t need.”
The American Chemistry Council, however, maintains that the organization’s intentions were benign.
“As an organization representing plastic makers, we are interested in research on plastic products,” says Allyson Wilson, public relations manager for the Council. “The overwhelming majority of reusable bags are plastic, so it’s important that we understand how consumers are using them so that we can communicate scientifically-based guidance on their proper use to the public. Reusable bags are a great choice, and the study’s findings underscore the importance of washing them regularly.”
While the trade group subsidized the study, it had no involvement with the research.
Although ChicoBag’s Keller has reservations about the study, he supports a “common sense” approach to keeping reusable bags clean and advises consumers to check their bags for washing instructions.
His company’s bags, which are made from woven polyester or PET plastic, can go in the washing machine with your other laundry. The bags tested in the study – mainly the 99-cent polypropylene bags you’ll find near the cash register of the grocery store – fare better when hand washed; they will wear out more quickly if washed in the machine regularly.
“You can also hang bags inside-out in direct sunlight to kill bacteria,” Keller says. “Sunlight really is the best disinfectant.”