2014-11-14 10:38:52

A reusable shopping bag, sometimes called bag for life, is a type of shopping bag which can be reused many times: this is an alternative of single use paper or plastic bags. It is often made from fabric such as canvas, woven synthetic fibers, or a thick plastic that is more durable than disposable plastic bags, allowing multiple use.

Reusable shopping bags are a kind of carrier bag, which are available for sale in supermarkets and apparel shops. Reusable shopping bags require more energy to produce than common plastic shopping bags. One reusable bag requires the same amount of energy as an estimated 28 traditional plastic shopping bags or eight paper bags. "If used once per week, four or five reusable bags will replace 520 plastic bags a year" according to Nick Sterling, research director at Natural Capitalism Solutions. ^[1] A study commissioned by the United Kingdom Environment Agency in 2005 but never published found that the average cotton bag is used only 51 times before being thrown away

Most reusable bag shoppers do not wash their bags once they return home and the bags may be leading to food poisoning according to Dr. Richard Summerbell, research director at Toronto-based Sporometrics and former chief of medical mycology for the Ontario Ministry of Health.^[11] Because of their repeated exposure to raw meats and vegetable there is an increased risk of foodborne illness. A 2008 study of bags, sponsored by the Environmental and Plastics Industry Council of Canada, found mold and bacterial levels in one reusable bag to be 300% greater than the levels that would be considered safe in drinking water.^[12][13] The study does not differentiate between non-hemp bags and hemp bags, which have natural antimildew and antimicrobial properties.^[14]

A 2010 joint University of Arizona and Limo Loma University study (sponsored by the American Chemistry Council, a trade group that advocates on behalf of disposable plastic bag manufacturers) they found that "Reusable grocery bags can be a breeding ground for dangerous foodborne bacteria and pose a serious risk to public health".^[15] The study found that 97% of users did not wash them and that greater than 50% of the 84 bags contained coliform (a bacteria found in fecal material), while E. coli was found in 12% of the bags.^[16] The study made the following recommendations:

1. States should consider requiring printed instructions on reusable bags indicating they need to cleaned or bleached between uses.
2. State and local governments should invest in a public education campaign to alert the public about risk and prevention.
3. When using reusable bags, consumers should be careful to separate raw foods from other food products.
4. Consumers should not use reusable food bags for other purposes such as carrying books or gym clothes.
5. Consumers should not store meat or produce in the trunks of their cars because the higher temperature promotes growth of bacteria, which can contaminate reusable bags.

The study further showed that machine or hand washing even without the presence of bleach was effective in reducing coliform and other bacteria in the bags to levels below detection.^[17]

A Consumer Reports article criticized the 2010 study, calling into question the small sample size of bags examined in the study and the questionable danger of the type and amount of bacteria found. Michael Hansen, senior staff scientist at Consumers Union, stated "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." But Hansen notes that there are some reminders to take away from the study. It’s easy to spread bacteria from meat, fish, or poultry to other foods – in your kitchen or in your grocery bags. So he does think it’s wise to carry those items in disposable bags. Reusable bags are fine for most everything else, but it’s a good idea to wash them occasionally.

http://en.wikipedia.org/wiki/Reusable_shopping_bag