A string of major retailers pulled plastic products with bisphenol A off their shelves on Thursday, part of a purge at stores across the country in anticipation of a Health Canada warning that the chemical is dangerous.

Sears Canada, Rexall Pharmacies, London Drugs and Home Depot Canada were among the latest retailers to remove such products as plastic baby bottles and reusable water bottles made with bisphenol A, or BPA, from their stores.

The advocacy group Environmental Defence issued a press release congratulating those stores "for taking action to protect Canadians' health."

"The wave of change we've seen in the past few days is absolutely remarkable," said Dr. Rick Smith, the group's executive director.

The fallout began when the Globe and Mail reported on Tuesday that an imminent Health Canada announcement would classify BPA as a dangerous substance, a move the newspaper said would be a first for a regulatory body worldwide.

Government sources confirmed to CBC that an announcement could be made as early as Friday. Health Canada and Environment Canada have scheduled a news conference for 12:30 p.m. Friday to make an "important announcement."

Even if Health Canada, along with Environment Canada, releases a draft assessment of BPA, a 60-day public comment period will follow. Ottawa then has a year to issue a report outlining how to control exposure.

But many of the country's largest retailers are refusing to wait for it to become official and have already begun removing BPA products from their shelves in response to consumer concerns.

Among the retail giants that announced they would rid their stores of products containing bisphenol A are Wal-Mart Canada, Canadian Tire, Hudson's Bay Co., and Forzani Group, Canada's largest sporting goods retailer.

"Sales of BPA products have largely dried up in the last month, so this is primarily driven by consumers, their desire to have alternatives and to assist them in clearing the marketplace of any confusion," Hillary Marshall, a spokeswoman for the Hudson's Bay Co., told CBC News.

Sudden ban could be devastating

But the packaging industry warns that a sudden ban on BPA could have a devastating economic impact, forcing people out of work in a number of industries.

"I think a ban, if it was immediate, would have drastic effects," said Larry Dworkin, spokesman for the Packaging Association of Canada.

Health Canada began reassessing BPA, along with a number of other chemicals, in November 2007. The review was looking at human and animal studies around the world into how much of the chemical is leaching from consumer products.

The plastics industry has vigorously defended the chemical, noting that it's been widely used for 50 years.

BPA is a synthetic chemical compound found in some hard clear plastics and resins such as food and drink containers, compact disks, electronics and the liner in many metal cans.

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.