Food cans sold by Canadian and U.S. retailers still frequently contain bisphenol A or BPA, according to a new report by environmental advocates.

Environmental Defence said 18 of 21 cans purchased in Ontario contained BPA, which mimics the hormone estrogen in animal studies. Studies on exposure in humans also suggest associations with health effects in children and adults.

Bisphenol A is used to make polycarbonate plastics and can be found in the coatings of food and drink packaging to prevent bacterial contamination, including botulism, as well as spoilage.

As a precaution given the uncertainty over BPA's potential effects in infancy and early childhood, Health Canada and the U.S. Food and Drug Administration have banned the use of BPA in baby bottles and sippy cups.

"To see this many years later it's still so common in cans, that's a huge problem because we've only learned more and more about how harmful this chemical can be," said Maggie MacDonald, toxic program manager for Environmental Defence in Toronto. 

Toxic Cans Too Scary

Some food companies have moved to stop the use of BPA in the linings of their cans. (Eric Risberg/Associated Press)

In 2014, Health Canada concluded that dietary exposure to BPA through food packaging "is not expected to pose a health risk to the general population, including newborns and infants."

The report by Environmental Defence and five other non-profit groups says exposure to even parts per trillion increases risk of breast and prostate cancer, infertility, Type-2 diabetes, obesity, asthma and behavioural changes including attention-deficit disorder.

"It is likely that people are exposed to BPA from canned foods at levels that are compromising our health," the report's authors said.

The groups called on national brands and retailers to:

  • Set a time frame to eliminate BPA and switch to safe substitutes in the lining of canned foods and other food packaging.
  • Label the presence of BPA and BPA-alternatives in can linings.
  • Publicly disclose safety data for BPA alternatives.

They urged consumers to avoid canned foods when possible in favour of fresh or frozen and to purchase canned food from manufacturers and retailers that fully disclose the type and safety of their can linings.

Low dose effects

Neuroscientist Deborah Kurrasch of the University of Calgary uses mice and zebrafish to understand how chemicals in the environment affect the brain.

Kurrasch believes there is a consensus within the scientific community about the potential harmful effects of BPA. As a mother, she limits use of plastic containers for food, but found that sending her sons off to soccer with glass bottles wasn't practical.

Traditionally in toxicology, the "dose makes the poison."  

For endocrine disruptors such as BPA, "you can have effects at very low doses," Kurrasch said in an interview.

Asked why regulators in Canada, the U.S. and Europe haven't acted, Kurrasch said they use a higher burden of proof of harm.

"I think that we're rapidly moving towards that burden of proof," she said.

Kurrasch is hopeful that regulators and academic scientists will come together. In the meantime, consumers should be prepared to start paying more for canned goods that don't use BPA.

The safety of alternatives to BPA also needs to be checked, Kurrasch said. 

Food & Consumer Products of Canada, which represents manufacturers of products in grocery stores, said both the group and its members "take this issue very seriously and safety is paramount."

"Canada's current regulatory system for BPA is one of the most stringent in the world. BPA is also a highly tested substance and at current levels of exposure governments globally continue to recognize its current use in can linings as safe. We rely on the sound science conducted at Health Canada to inform our decisions on the selection of safe materials,"  Susan Abel, vice-president safety and compliance at Food & Consumer Products of Canada, said in a statement.

Campbell's  said it will stop using BPA by mid-2017, while Del Monte said it would start this spring to eliminate it. ConAgra Foods, Inc., made the transition to BPA-free cans last year.

Clarifications

  • Food & Consumer Products of Canada represents manufacturers that produce products found on grocery store shelves, not the stores themselves.
    Mar 31, 2016 1:20 PM ET