Reusable grocery bags rife with toxic bacteria - study

Staff ~ The Guardian
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This unsolicited news release just in:
Toronto (May 19, 2009) - While reusable shopping bags are being aggressively promoted by some grocery chains as an eco-friendly initiative, new evidence now suggests that these bags may not be so friendly to your health.
The evidence - "A Microbiological Study of Reusable Grocery Bags" - is the first study of its kind in North America. It looked at whether reusable grocery bags become an active bacterial growth habitat and breeding ground for yeast and mold after persistent use and pose a public health risk.
Swab-testing of a scientifically-meaningful sample of both single-use and reusable grocery bags found unacceptably high levels of bacterial, yeast, mold and coliform counts in the reusable bags.
"The main risk is food poisoning", said Dr. Richard Summerbell, Director of Research at Toronto-based Sporometrics and former Chief of Medical Mycology for the Ontario Ministry of Health (1991-2000), who evaluated the study results. "But other significant risks include skin infections such as bacterial boils, allergic reactions, triggering of asthma attacks, and ear infections."
The swab testing was conducted March 7-April 10th, 2009 by two independent testing laboratories. The study found that 64% of the reusable bags were contaminated with some level of bacteria and close to 30% had elevated bacterial counts higher than the 500 CFU/mL considered safe for drinking water.
Further, 40% of the bags had yeast or mold, and some of the bags had an unacceptable presence of coliforms, faecal intestinal bacteria, when there should have been 0.
Some of the conclusions of the study are:

· The moist, dark, warm interior of a folded used reusable bag that has acquired a small amount of water and trace food contamination is an ideal incubator for bacteria. (see report)

· The strong presence of yeasts in some bags indicates the presence of water and microbial growth substrate (food). The yeasts are thus a 'canary in the mine' confirming that microbes are growing in the bag.

· There is a potential for cross-contamination of food as the same reusable bags are used on successive trips; and

· Check-out staff in stores may be transferring these microbes from reusable bag to reusable bag as the contaminants get on their hands.

· In cases of food poisoning, experts are now going to have to test reusable bags in addition to food products as the possible sources of contamination.

"A growing problem that is of high concern", added Summerbell, "is possible exposure to the superbug called 'community-acquired MRSA' if the reusables are used to transport gym clothes or diapers in addition to groceries."

MRSA (methycillin-resistant Staphylococcus aureus) is a highly antibiotic-resistant form of a common infectious bacterium. It was first known mainly in hospital settings and demonstrated an ability to spread on contaminated surfaces, such as unwashed hands and items they touched.

One worrisome factor about CA-MRSA is that unlike the original S. aureus, it appears to be able to invade skin that has not been wounded and appears to cause a transmissible disease. The bacterium may enter grocery bags if they are re-used to carry athletic equipment. This is concerning because over 50% of the reusables tested in this study were used as multi-purpose totes to carry everything from books to gym equipment and groceries.

"The presence of faecal material in some of the reusable bags is particularly concerning," said Summerbell. "All meat products should be individually wrapped before being placed in a reusable bag to prevent against leakage. This should become a mandated safety standard across the entire grocery industry."

The study has been sent to the federal Sub-Committee on Food Safety currently investigating the safety of Canada's food system, federal and provincial health ministers and their deputies, as well as medical organizations across the country with a request for immediate action.

The research was conducted by Guelph Chemical Laboratories and Bodycote Testing Group of Montreal. Oversight and evaluative commentary on the results was undertaken by Toronto-based Sporometrics, the foremost experts in many aspects of fungal and environmental bacterial testing in Canada. GCL tested 23 used reusables and Bodycote tested two older used bags (2 and 3 years old). The Environment and Plastics Industry Council agreed to fund the testing.

Organizations: Sporometrics, Medical Mycology, Ontario Ministry of Health Guelph Chemical Laboratories Committee on Food Safety Bodycote Testing Group of Montreal Environment and Plastics Industry Council

Geographic location: Toronto, North America, Canada

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Recent comments

  • Smoke and Mirrors
    June 21, 2010 - 20:39

    Well, If you go to any other store than Superstore, you can still get plastic bags. I take Sobey's bags to Superstore IF I go. It has meant much more business for Sobeys. We always reuse our grocery bags for garbage, doggy bags etc. I notice Superstore is still selling PLASTIC garbage bags?? What is the difference?

  • Insider
    June 21, 2010 - 20:35

    Free disposable bags at sobey's

    Boo to Superstore

  • more FEAR mongering
    June 21, 2010 - 20:30

    Okay, so like everything else you re-use, wash them once in a while!

  • What is Next !?
    June 21, 2010 - 20:29

    Maybe it's time to find a new world to live in !!!

  • Dawna
    June 21, 2010 - 20:22

    Don't you think we are being paranoid? After all, Money is the dirtiest thing you can handle, and it doesn't matter who packed your groceries, or in what container. I don't see anyone washing their hands after handling money. Do you?????
    If you are that concerned about bags, etc. wash off your groceries when you get home, I do! I wipe off everything, and I wash my veggies, and fruit.
    I don't worry about the bags ( I bought Sobeys reusable ones) but how many people handled my groceries before I bought them?? Takes a couple of minutes, but I feel they are cleaner for it!

    I never heard of anyone dying because of dirty grocery bags!! Think about it! We are lucky we can afford to put something in those bags, or gym bags etc. Have a good day!!!

  • Emily
    June 21, 2010 - 20:19

    Get BAGGU reusable bags. They are machine washable, so you can keep them clean easily.

  • Cookie
    June 21, 2010 - 20:16

    Re Only in North America comment.I thought everyone knew that handbags/purses should not be set on the floor, where germ-covered footwear has been,and then later put onto a counter or table.We may as well be eating off the floor. People-USE YOUR HEAD !!

  • Willy
    June 21, 2010 - 20:16

    This is the study in its entirety:
    As you can see on the very first page, it has been either done or paid for by EPIC, the Environment and Plastics Industry Council, who are, according to their own website ( a standing committee of CPIA, the Canadian Plastics Industry Association.

  • Bill
    June 21, 2010 - 20:15

    We've been using them for years as our local NO FRILLS store has always charged .05 for plastic bags. We just throw them in the washing machine every couple of weeks. Not a big deal really!

  • Kaodake
    June 21, 2010 - 20:14

    Scare tactic story.

    Wash the bags regularly and use common sense.

    Stores can make recycled paper bags available (remember paper bags?).

    Problem solved.

    June 21, 2010 - 20:09

    So if you are smart enough to tell weather or not your Reusable Bags are contaminated then you take them to your washing machine, add phosphates, soap javex etc. Turn the washing machine by burning energy. After washing these bags multiple times and adding all that crap to the environment while burning all that energy , we are left with worn out bags that go to THE LAND FILL SITES...LOBLAWS are using the GREEN word to add 50 million to there bottom line . Nothing more nothing less.

  • BagguGirl
    June 21, 2010 - 20:09

    I've used reusable bags for years. And I spent a little bit of extra money and got ones that are easily washed. I agree with the above, anything is disgusting if you don't wash it. It's reusable -- not antibacterial. Baggu Bags are little more expensive than the cheap ones at the store, but you toss them in with the wash and hang them to dry and you're tickety boo!

  • Try washing them!!
    June 21, 2010 - 20:04

    Here's a thought. WASH THEM!

    Don't put your stinky sneakers in it, covered in dog droppings.. then go to the superstore!!

    Not rocket science folks!!

  • LA
    June 21, 2010 - 19:57

    Well if I ever accidentally spill chicken blood in my reuseable bag, I'm not likely to let my cookies soak in it.

  • Silent
    June 21, 2010 - 19:56

    So says a study paid for by the plastic bag lobby

  • Dave
    June 21, 2010 - 19:45

    Well the Superstore cashier didn't have a problem with my hockey bag and neither do I. I personally enjoy the sweet scent of sweat guinness and pickled onions.

  • It isn't smart
    June 21, 2010 - 19:40


    We switched from paper to plastic because environmentalist know-betters said it was better for the environment.

    Tune the wacky greenies out.

  • Only in
    June 21, 2010 - 19:40

    The Environment and Plastics Industry Council agreed to fund the testing. Now wasn't that mighty neighbourly of them.

    Anyway, reusable shopping bags, baskets, totes, string bags, etc.,etc. were in use in Europe many years ago when I lived there. If they can do it without poisoning each other, so can we. No one ever did a study on what gets transferred by the bottom of ladies purses to the check out counters in stores, have they? I bet there'd be some stomach churning things found there. Difference is that the plastic bag makers can't hope to make money off that study.

    We should just go back to paper bags (recycled paper anyone?), the kind of paper bags that were used before we jumped on the plastic is better boat and ended up polluting our seas and land and air.