By Kim O’Hare
A move by the Canadian government in late April has caught the attention of health conscious people around the world. Canada announced its intention to ban the import, sale and advertising of baby bottles with the controversial chemical bisphenol A (BPA). That could be just the tip of the iceberg, since the chemical is widely used in many food containers ranging from plastic drink bottles to food storage containers.
The proposal marks the beginning of a mandatory 60-day consultation period. The announcement comes after a lengthy review of the chemical under the government’s Chemicals Management Plan. Recent research has shown that bisphenol A is an estrogenic hormone disrupter that causes reproductive damage and may lead to prostate and breast cancer in adulthood. Babies are particularly vulnerable, since most traditional plastic baby bottles leach bisphenol A into the milk they drink.
“Although our science tells us that exposure levels to newborns and infants are below the level that cause effects, we believe that the current safety margin needs to be higher. We have concluded that it is better to be safe than sorry,” said a government release.
While the proposed ban does not include sale, import and advertising of water bottles and other food containers, major retailers across the country were pulling plastic drink containers containing BPA off store shelves within hours of the announcement. Retailers say demand for baby products with the controversial chemical come to an abrupt halt.
Depending on whom you talk to, BPA is either perfectly safe or a dangerous health risk. The plastics industry says it is harmless, but a growing number of scientists are concluding, from some animal tests, that exposure to BPA in the womb raises the risk of certain cancers, hampers fertility and could contribute to childhood behavioural problems such as hyperactivity.
According to its critics, BPA mimics naturally occurring estrogen, a hormone that is part of the endocrine system, the body’s finely tuned messaging service. “These hormones control the development of the brain, the reproductive system and many other systems in the developing foetus,” says Frederick vom Saal, Ph.D., a developmental biologist at the University of Missouri. Endocrine-disrupting chemicals can duplicate, block or exaggerate hormonal responses. “The most harm is to the unborn or newborn child,” vom Saal says.
BPA is not some new kid on the chemical block. It was first discovered in the 19th century and concerns about health risks were first raised in the 1930’s. It was thrust into the spotlight by a laboratory mishap in August 1998. An American geneticist noticed chromosomal errors in the mouse cells she was studying had shot up - from one or two percent to 40 percent. She traced the effect to polycarbonate cages and water bottles that had been washed with a harsh detergent. When her team replaced all the caging materials with non-polycarbonate plastics, the cell division returned to normal.
Concern over bisphenol is likely to spread due to its wide use. If you consume canned soups, beans and soft drinks (organic or not) you may be swallowing residues of BPA that can leak out of the tin linings into your food. Nearly all tin can liners contain BPA, says the Can Manufacturers Institute.
Part of the problem lies in the chemical’s tenacious behaviour. BPA has been found to leach from bottles into babies’ milk or formula; it migrates from tin liners into foods and soda and from epoxy resin-lined vats into wine; and it is found in the mouths of people who’ve recently had their teeth sealed. Ninety-five percent of Americans were found to have the chemical in their urine in a 2004 biomonitoring study by the Centers for Disease Control and Prevention (CDC).
If you own polycarbonate bottles, including those hard plastic refillable bottles that have become so popular in recent years, Check the bottom for a number #7 inside the recycling symbol. If you have a bottle like that, wash it by hand, away from the extreme heat and harsh cleansers of a dishwasher, to avoid degrading the plastic and increasing leaching of BPA.
Look for cracks or cloudiness on your reusable clear plastic bottles. Use glass baby bottles or plastic bag inserts, which are made of polyethylene, or switch to polypropylene bottles that are labelled #5 and come in colours or are milky rather than clear. Choose soups, milk and soy milk packaged in cardboard “brick” cartons, by Tetra Pak and SIG Combibloc, which are made of safer layers of aluminium and polyethylene (#2) and also recyclable.
Eat fresh foods in season and save the canned foods for convenience or emergencies. The exception is some canned fruit such as that found in smaller fruit-cocktail cans, which do not require a liner, according to the Can Manufacturers Institute. Some wines have been found to contain up to six times the BPA of canned foods. While most wines probably don’t, it’s another good reason to drink in moderation.
There are seven classes of plastics used worldwide in packaging applications. Type 7 is the catch-all “other” class, and some type 7 plastics, such as polycarbonate (sometimes identified with the letters “PC” near the recycling symbol) and epoxy resins, are made from bisphenol A monomer. When such plastics are exposed to hot liquids, bisphenol A leaches out 55 times faster than it does under normal conditions,
Types 2, 4, and 5 are believed to not leach chemicals in any significant amount. Type 1 and Type 6 have unreacted phthalates and styrene, respectively, which could leach under certain conditions, but these resins do not use bisphenol A during polymerization and package forming.