BPA is found in food cans and some plastic containers. (Jim Young/Reuters)

Bisphenol A, or BPA, a chemical used to make some hard plastic containers and toys, has formally been declared a toxic substance by Canadian authorities.

The federal government added BPA to Canada's toxic substances list on Wednesday.

"We are continuing our leadership on this issue and Canadians can rest assured that we are working hard to monitor and manage bisphenol A," Environment Minister Jim Prentice said in a statement.

BPA, also found in resins that coat the interior of food cans to prevent corrosion, has been shown to mimic the hormone estrogen and does not occur naturally in the environment.

There is no smoking gun indicating how dangerous BPA is, but the evidence is adding up, said Bruce Lanphear, a senior scientist at the child and family research institute at B.C. Children's Hospital.

Studies in animal models are "quite concerning," and raise questions about prostate disease, breast cancer, fertility issues and behaviour problems in children, Lanphear said.

In August, Statistics Canada reported that measurable levels of BPA were found in the urine of 91 per cent of Canadians aged six to 79.

"Health Canada considers that sufficient evidence relating to human health has been presented to justify the conclusion that bisphenol A is harmful to human life and should be added to Schedule 1 of [the Canadian Environmental Protection Act]," the federal government reported in the Canada Gazette.

The government said the listing allows it to develop regulations to manage the risks posed by the chemical.

In 2008, Canada proposed declaring BPA toxic because of reproductive and developmental toxicity and environmental effects. The federal government proposed that BPA be banned in baby bottles and limited in infant formula cans.

But BPA was not added to the toxic substances list at that time.

Some like, some don't

Rick Smith, executive director of the Toronto advocacy group Environmental Defence, applauded Wednesday's announcement.

"It's a great victory for every mom and dad who sent a letter to their MP demanding that the federal government do a better job protecting the health of Canadians," Smith said.

The toxic listing is the foundation for any legal action, said Smith, who predicted BPA will be removed from food and beverage containers in a few years.

Ottawa's move differs from other regulators worldwide, said Steven Hentges of the American Chemistry Council, a Washington-based industry group that represents plastics makers.

“Just days after the European Food Safety Authority (EFSA) once again confirmed that BPA is safe for use in food-contact items, Environment Canada’s announcement is contrary to the weight of worldwide scientific evidence, unwarranted and will unnecessarily confuse and alarm the public," Hentges said in a statement.