Increasing numbers of people are worried about the potential health risks of Bisphenol A (BPA) leaching from the liner into the food and the internet is full of claims and counter claims.
Nearly all tin cans, aluminium cans and metal tubes are BPA lined and have been since the 50s.
The liner can be white or yellow or transparent in which case it is undetectable. In most cases it is best to assume that your can has a plastic liner and that it contains BPA. The only way to know for sure is to phone the manufactorer and ask.
Some companies are bucking the trend – you can find a list of BPA free tins here.
So far so BPA but is it really that bad??
The following chart was taken from the very informative and interesting Wikkipedia article but you can find the same information all over the internet
Low dose exposure in animals
|Dose (µg/kg/day)||Effects (measured in studies of mice or rats,descriptions (in quotes) are from Environmental Working Group)||Study Year|
|0.025||“Permanent changes to genital tract”||2005|
|0.025||“Changes in breast tissue that predispose cells to hormones and carcinogens”||2005|
|1||long-term adverse reproductive and carcinogenic effects||2009|
|2||“increased prostate weight 30%”||1997|
|2||“lower bodyweight, increase of anogenital distance in both genders, signs of early puberty and longer estrus.”||2002|
|2.4||“Decline in testicular testosterone”||2004|
|2.5||“Breast cells predisposed to cancer”||2007|
|10||“Prostate cells more sensitive to hormones and cancer”||2006|
|10||“Decreased maternal behaviors”||2002|
|30||“Reversed the normal sex differences in brain structure and behavior”||2003|
|50||Adverse neurological effects occur in non-human primates||2008|
|50||Disrupts ovarian development||2009|
The current U.S. human exposure limit set by the EPA is 50 µg/kg/day.
So why the hell is BPA still being used you might ask while checking your pants nervously and belting the kids.
Here’s some information from the bishenol-a.org
Metal food and beverage cans have a thin coating on the interior surface, which is essential to prevent corrosion of the can and contamination of food and beverages with dissolved metals (UK FSA, 2002).
In addition, the coating helps to prevent canned foods from becoming tainted or spoiled by bacterial contamination.
The major types of interior can coating are made from epoxy resins, which have achieved wide acceptance for use as protective coatings because of their exceptional combination of toughness, adhesion, formability and chemical resistance.
Such coatings are essentially inert and have been used safely for over 40 years. In addition to protecting contents from spoilage, these coatings make it possible for food products to maintain their quality and taste, while extending shelf life.
Based on the results of the SPI study, the estimated dietary intake of BPA from can coatings is less than 0.00011 milligrams per kilogram body weight per day. This level is more than 450 times lower than the maximum acceptable or “reference” dose for BPA of 0.05 milligrams per kilogram body weight per day established by the U.S. Environmental Protection Agency.
Stated another way, an average adult consumer would have to ingest more than 230 kilograms (or about 500 pounds) of canned food and beverages every day for an entire lifetime to exceed the safe level of BPA set by the U.S. Environmental Protection Agency.
In 2002, the safety of epoxy resin can coatings was confirmed by an analysis of the European Commission’s Scientific Committee on Food (SCF).
Consequently, the potential human exposure to BPA from can coatings is minimal and poses no known risk to human health. Can coatings have been and continue to be recognized as safe by the U.S. Food and Drug Administration, the U.K. Food Standards Agency, the EU Scientific Committee on Food and other government bodies worldwide.
for more go to bishenol-a.org
So who do you believe? Is this just a case of overreaction? Several scientific panels including the European Union’s Scientific Committee on Food, the National Toxicology Program and the Harvard Center for Risk Analysis have concluded that the claims that low doses of BPA affect human health have not (yet ), been substantiated. While accepting that animal testing has produced adverse results they can find no concrete evidence that humans will react the same way.
Incidentally if BPA does affect animals, surely we need be reassured that BPA is not leaching into say river water from rubbish dumps for example. I keep on hearing claims that man frogs are turning into ladies as are fish – and it has been long been suggested there is a link with estrogen in the water? Well I don’t know but that’s my point – no one seems to know for sure.
What is certain is that BPA is a $6 billion global industry.According to the National Institutes of Health, approximately 940,000 tons of BPA are produced in the U.S. per year. About 21% is used in epoxy resins and most of the rest goes to polycarbonate. These facts and lots more can be found in this extremely interesting article by Melody Voith. She quotes the North American Metal Packaging Alliance as saying “BPA and other materials are reacted to form high-molecular-weight epoxy polymers, which are further cross-linked during the curing process to form a chemically resistant coating.” and the American Chemistry Council as asserting that exposure to BPA from can coatings is less than 0.00011 mg per kg of body weight per day, less by a factor of 450 than the 0.05 mg maximum acceptable dose set by the Environmental Protection Agency. Interesting.
It must also be noted that despite claims that BPA is as safe as safe, research is ongoing into alternatives. And maybe they have found one. According to Food Production Daily
“Researchers in the United States have developed a chemical derived from sugar with the potential to replace bisphenol A (BPA) in a number of products, including the lining of food cans. The New Jersey Institute of Technology (NJIT) said Professor Michael Jaffe had received a US patent for an epoxy resin based on isosorbide diglycidyl ether that could make consumer products safer.
“The patent will enable us to create a family of isosorbide-based epoxy resins that have the potential to replace bisphenol A in a number of products including food can linings”, Jaffe told FoodProductionDaily.com.
Note the claim by food production Daily that this will make consumer products safer. Needless to say the creators of this new product are clear in their statements that BPA is not a good thing.
Hmmm – the choice is yours. As for me I boycott nearly all tins – tonic and tomatoes are the exceptions.
- BPA Exposure ‘Much Higher’ Than Believed & Proposed BPA Ban (crunchydomesticgoddess.com)
- New Health Canada and FDA Studies Support BPA Safety (eon.businesswire.com)
- Global Epoxy Resins Market to Reach 1.93 Million Tons by 2015, According to a New Report by Global Industry Analysts, Inc. (prweb.com)
- Statscan survey finds BPA present in 91 per cent of Canadians (theglobeandmail.com)