Reusable 'green bags' harbor germs if not washedWash those reusable bags. That’s a key piece of advice for users of so-called green bags from public health experts and researchers.
By: Brandi Jewett, Herald Staff Writer
Wash those reusable bags. That’s a key piece of advice for users of so-called green bags from public health experts and researchers.
More Grand Forks shoppers are using these bags in lieu of disposable plastic bags. Some local grocery stores are encouraging the practice, and businesses give green bags away as promotions.
But not many users wash them, and some university studies suggest that could put their health at risk.
“Bacteria growth is possible in these types of bags, especially cloth ones that come into direct contact with raw food, like produce,” said Tim Haak, environmental health supervisor for Grand Forks Public Health.
Critics said the studies use too small a sample and they’re funded by the plastic industry, which has been opposing efforts to ban disposable bags in a number of U.S. cities.
One of the more widely quoted studies is a 2010 University of Arizona and Loma Linda University study. In a sample of 84 reusable bags, it found that 12 percent tested positive for E. coli bacteria, which can cause serious food poisoning if consumed.
The number of bacteria increased 10 times when researchers added meat juice to bags and stored them for two hours in the trunks of cars, the way many bags are stored.
Interviews with the owners of the bags found that 97 percent didn’t wash the bags on a regular basis and 75 percent put meat and produce in the same bag.
Funding for the study came from the American Chemistry Council.
Another study, funded by the Canadian Plastics Industry Association, found similar results in 2009. Nearly 30 percent of the 25 bags tested had bacteria counts higher than what is “considered safe for drinking water,” the study said.
It also found that reusable bags do double duty for some people as both grocery and gym bags. The study theorized that drug-resistant bacteria that cause staph infections, which may be found on gym equipment, could contaminate the bags.
Consumer Reports said in its July 2010 issue that the 2010 study should be taken with a grain of salt. The sample size of 84 bags was too small, and the study may inflate the danger.
“A person eating an average bag of salad greens gets more exposure to these bacteria than if they had licked the insides of the dirtiest bag from this study,” Michael Hansen, a senior staff scientist at Consumers Union told the magazine. “These bacteria can be found lots of places, so no need to go overboard.”
Consumer Reports also had one more beef with the study: It was funded by the plastic industry.
Soap and water are really all that’s needed to decontaminate the bags.
The 2010 study said that more than 99.9 percent of germs were gone after hand- or machine-washing. The other option, the study said, is to just use disposable bags.
Besides keeping your bags clean, another way to prevent the spread of food-borne illness is to use each bag for a specific purpose, color coding them if needed, according to Julie Garden-Robinson, a food and nutrition specialist for the NDSU Extension Service.
Bag meat separately from produce and other foods that won’t be cooked. Each piece of meat should also be in its own bag, typically a disposable produce bag, so meat juice is contained.
Although this idea defies the no-plastic rule, it helps prevent cross-contamination, which is a major food safety issue,” Garden-Robinson wrote.
“We cook chicken to an internal temperature of 165 and ground beef to160,” she wrote. “If chicken juice has contaminated the beef, you might not cook it to an internal temperature that inactivates the bacteria associated with chicken.”
Haak also recommended not storing bags used for transporting groceries in the trunk of a vehicle. “If you have spilled milk or blood sitting in a hot trunk, the bacteria growth will be substantial,” he said.
And he said use separate bags for the groceries and for gym gear.
On the web:
n To see the University of Arizona study, go to tinyurl.com/gfbags.
n To see the Canadian Plastics study, go to tinyurl.com/gfbags2.
n To see the Consumer Reports article, go to tinyurl.com/gfbags3.
Reach Jewett at (701) 787-6736; (800) 477-6572, ext. 2736; or send email to firstname.lastname@example.org.