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Bisphenol A: FAQs

In December 2007, Vancouver-based Mountain Equipment Co-op became the first major Canadian retailer to pull polycarbonate containers from its store shelves. (University of Cincinnati Academic Health Center Communication Services/Canadian Press)

The buzz on bisphenol A — the controversial chemical used to make many hard plastic toys, bottles and food containers — is proving perplexing for many consumers and retailers. As the ever-growing debate about the potential health effects of BPA rages on, consumers are left puzzled as to whether they should keep or clear their cupboards of polycarbonate products.
On the one hand, recent animal studies theorize the chemical may be linked to obesity, infertility and insulin-resistance in rodents. Conversely, the plastics industry — including bottle maker Nalgene — vigorously defends the chemical, noting it has been used widely for 50 years.
Meanwhile, Health Canada, which has long held that the chemical poses no health risks, is set to release a preliminary report on BPA in May. Similarly, the U.S. Food and Drug Administration (FDA) says it is reviewing the chemical's safety, but noted that it does not consider normal BPA exposure to be hazardous.

What is bisphenol A?

Bisphenol A is a chemical compound found in some hard, clear, lightweight plastics and resins. It's used in the production of various types of food and drink containers, compact discs, electronics and automobile parts, and as a liner in some metal cans. Animal studies suggest that, once ingested, BPA may imitate estrogen and other hormones, according to the National Institutes of Health.

How do I know if my container contains bisphenol A?

Some polycarbonate containers are marked with the code number 7 on the bottom, but this doesn't necessarily mean that the item contains BPA. If unsure, call the manufacturer and ask about the BPA content in the product.

What does current research suggest about exposure to the chemical?

Studies in peer-reviewed journals have indicated that even at low doses, the chemical can increase breast and ovarian cancer cell growth and the growth of some prostate cancer cells in animals.
Yale researchers found that when BPA was administered to pregnant mice, it altered a gene responsible for normal uterine development. The study, published in the Journal of the Federation of American Societies for Experimental Biology in January 2007, theorized that, "If pregnant women are exposed to the estrogen-like properties found in BPA, it may impact female reproductive tract development and the future fertility of female fetuses the mother is carrying."
A study published in the journal Chemistry & Biology in 2006 showed that "modified versions of bisphenol A likely to be formed in the body do stimulate breast tumour cell growth in vitro," according to a statement by Theodore Widlanski, the study's lead researcher and a biochemistry professor at Indiana University. "Enzymes present on the surface of breast tumour cells appear to convert the modified BPA back into BPA."
He cautioned that the study, by researchers at Indiana University and University of California at Berkeley, did not indicate products such as bottled water aren't safe.
"We have only demonstrated a possible mechanism that explains what people have been speculating about for years." he said. "It doesn't mean that your bottled water is any less safe today than it was yesterday. It just means that if it isn't safe, we might be able to explain why."
A University of Cincinnati research team published a study in the journal Endocrinology in 2005 showing bisphenol A may disrupt important effects of estrogen in the developing brains of rodents. They worked with rats at a period in their development equivalent to the third trimester of human fetal development, through to the first few years of childhood. At low doses, bisphenol A appeared to affect the normal activity of estrogen.
"We have now shown that environmental estrogens like BPA appear to alter, in a very complicated fashion, the normal way estrogen communicates with immature nerve cells," said lead researcher Jay Belcher in a statement. "The developmental effects that we studied are known to be important for brain development and also for normal function of the adult brain."
In 2003, researchers at Case Western Reserve University in Cleveland published in the journal Current Biology the results of studies of low levels of exposure of the chemical on the reproductive systems of mice. They found that the mice's eggs showed increased rates of two chromosome abnormalities. In normal mouse or human eggs, the chromosomes line up, ready for the egg to split in two when fertilized. But in many of the eggs of the exposed mice, the chromosomes were not aligned. In addition, the egg cells of the exposed mice often had too few or too many chromosomes.
These kinds of chromosomal abnormalities are the leading cause of birth defects and mental retardation in humans, according to Patricia Hunt, the study's lead researcher and a professor of genetics.

What is Health Canada's take on the chemical?

Health Canada launched an evaluation of bisphenol A in 2007, including a review of human and animal studies around the world and research into how much of the chemical is leaching from consumer products.
The evaluation is expected to be complete in the spring of 2008. The study is part of a more comprehensive review of about 200 chemicals the federal government has singled out for more careful study.
While acknowledging concerns over the chemical, Health Canada's pre-evaluation take on bisphenol A plays down potential health effects. On its website, the department says only residual levels of BPA are found in the consumer products, because most of it is consumed during the manufacturing process.
"Analysis and testing conducted by Health Canada in 2000/2001 on plastic baby feeding bottles and other plastic products showed that the levels of bisphenol A in these products were exceedingly low, and did not present a risk to Canadian children," it said.
"Health Canada's investigation also showed that although low amounts of bisphenol A could migrate from the plastic into milk, it would do so only under conditions of extreme use.… These results suggest that plastic products do not pose a health risk if used properly."

How have Canadian retailers responded?

In December 2007, Vancouver-based Mountain Equipment Co-op became the first major Canadian retailer to pull polycarbonate containers from its store shelves. Tim Southam, a company spokesman, said consumers had expressed concern about the chemical. He noted MEC would revisit its decision should Health Canada rule the chemical does not pose any health risks.
Lululemon Athletica Inc., also Vancouver-based, announced plans later the same month to stop selling plastic water bottles that contain bisphenol A. The company did not pull bottles already in stores. Lululemon said it had followed the issue for more than a year before deciding it would switch to new water bottles made of acrylic.

What s can I use?

Use glass, stainless steel, or porcelain containers, especially for hot food or liquids.
For baby bottles, choose glass or look for hard plastic bottles without bisphenol A. They can be found at health food stores and some baby stores.
For preserved goods, opt for glass jars or canned goods that do not contain liners made with BPA.

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