Behind the bisphenol A controversy: a scientist speaks out

If you’ve picked up a Canadian newspaper lately, you’re probably aware of a controversial chemical called bisphenol A (BPA).

Used in the production of polycarbonate (PC) plastic, BPA has been labeled a health risk in Canada and seems under fire from all quarters.

At an outdoor rally in Toronto in November, for example, Ontario Premier Dalton McGuinty was urged to legislate against BPA, and his Ontario government promptly promised to launch an investigation into the chemical. In the wake of this, Canadian retailers such as Mountain Equipment Co-op and Lululemon Athletica yanked all PC bottles containing the chemical from their shelves.

Already, environmental groups like Toronto-based Environmental Defence have applauded these steps. “The dangers of BPA in food and drink are becoming clear, and it won’t be long before this chemical is gone completely from food and beverage containers,” said the group’s spokesperson.

So what exactly does BPA do, and is it really necessary to ban it from PC bottle production? To get a better understanding of the issue, Canadian Plastics spoke with Steve Hentges, Ph. D., executive director of the Polycarbonate/ BPA Global Group, a division of the Arlington, Va.-based American Chemistry Council.

Q: What factors have contributed to the recent headlines surrounding BPA?

A: Underlying the recent attention is the interest in BPA by scientists, who have conducted quite a few studies on BPA in recent years. Government bodies routinely review new scientific information that is relevant to the safety of common consumer products, for example Health Canada, with responsibility for regulating those products.

The combination of new scientific information and government reviews alone can generate attention when the safety of common products is in question. In addition, some environmental activists have taken advantage of the circumstances to indulge in scaremongering regarding the safety of consumer products.

Q: Can you briefly summarize some of the scientific research surrounding BPA?

A: In recent years, a hypothesis has been advanced that suggests that BPA can cause health effects at very low doses by disrupting the endocrine system. This hypothesis has stimulated quite a few studies on laboratory animals to test whether BPA may cause various reproductive or developmental effects. These studies vary widely in size, scope, quality, and perhaps most importantly, relevance to human health.

Government bodies around the world have comprehensively examined the science supporting the safety of BPA. In every case, these reviews support the conclusion that BPA is not a risk to human health at the trace residual levels present in consumer products made from PC plastic. Q: Can you quantify the level of exposure to BPA that can be expected from consumers purchasing bottles or other plastic products that contains this chemical?

A: In the manufacturing process for polycarbonate plastic, virtually all of the BPA is chemically reacted to form the plastic. Only trace residual levels of BPA, typically less than 60 parts per million, remain in the finished plastic. Consequently, there are no consumer products that contain significant levels of BPA and it is not possible for consumers to contact BPA at harmful levels from use of consumer products.

This has been recently confirmed in a population-scale biomonitoring study conducted by the U. S. Centres for Disease Control, which showed that typical human exposure to BPA from all sources is approximately 1,000 times below the safe level recently set by the European Food Safety Authority.

Q: What are the benefits of using BPA in PC plastic?

A: The largest use for BPA is to make PC plastic, which has a unique combination of attributes that make it useful in a wide array of products.

Among other properties, PC is lightweight, highly shatter-resistant and has good optical clarity and heat resistance. Common consumer products made from polycarbonate include CDs and DVDs, bicycle helmets, eyeglass lenses, incubators, components of medical devices, electronic product housings, automotive components, home food storage containers, and baby bottles.

BPA and PC plastic have been safely used for 50 years to make these products and many more. No alternative has been so well studied or so well vetted by government agencies.

While scaremongering may receive an inordinate amount of attention, what is often overlooked or poorly reported are the views of the many government bodies worldwide who have already reviewed the science, all of which supports the conclusion that BPA is not a risk to human health.