It's hard to walk down the kitchenware aisle in a Canadian store without noticing the "BPA-free" labels on plastic bottles and containers.

Consumers usually assume these labels mean products are safer, or better, because they do not contain the harmful chemical bisphenol A (BPA).

BPA is used to manufacture polycarbonate, the hard, clear plastic from which some bottles and other food containers are made. When foods are in direct contact with the plastic, small amounts of BPA may migrate into those foods, prompting increased public pressure to move away from its use.

But new research suggests the chemicals now used as substitutes for BPA, mainly other bisphenols, may have negative health impacts similar to those caused by BPA. Health and environmental advocates are raising questions about the safety of those substitutes.

And the record of what impact such products may have is confused, because there is little information for consumers on what substances are being used to replace BPA.

Chemicals like BPA... are being replaced by what are referred to as 'regrettable substitutes.' - Muhannad Malas, Environmental Defence

BPA has been used for more than 60 years and is also found in the epoxy resin that lines food cans, as well as items including baby bottles, teething rings, baby clothing, register receipts and dental sealants.

Manufacturers began using BPA substitutes in response to Canada's 2010 ban on BPA in baby bottles after an extensive assessment concluded it was toxic. International research found BPA was an endocrine disruptor, capable of interrupting the normal process of human growth and development, and may be linked to poor neurobehavioural functioning , obesity , and cancer .

The safety of BPA is still under debate.

Although the ban was primarily meant to protect infants, it resulted in the widespread introduction of "BPA-free" products, including reusable water bottles and lunch containers.

Substitutes show up in food, blood

But researchers are worried that the chemicals used to replace BPA, things like bisphenol S, bisphenol F and bisphenol B, are starting to show up in food, house dust, blood and urine.

These newer chemicals were chosen because they were similar enough to BPA to serve the same function — namely, to produce strong, clear plastics. But growing evidence suggests they may also be endocrine disruptors.

A 2019 study in the journal Toxicology reviewed hundreds of studies on two dozen different BPA substitutes and concluded that some "have health or toxicological effects at concentrations similar to or lower than BPA."

Then-federal health minister Tony Clement announces a plan in 2008 to ban the import and sale of plastic baby bottles containing BPA. Although the ban was primarily meant to protect infants, it resulted in the widespread introduction of 'BPA-free' products, including reusable water bottles and lunch containers. (Chris Wattie/Reuters)

In other words, these chemicals may have the same harmful effects as BPA, but at lower levels. Almost all of the BPA substitutes showed some hormonal influence, suggesting they could affect growth and reproduction.

"This is something that the scientific community has been warning regulators about for a very, very long time," said Muhannad Malas, toxics program manager at Environmental Defence, an advocacy group.

"Chemicals like BPA, that end up getting phased out through regulation or through voluntary corporate action, are being replaced by what are referred to as 'regrettable substitutes.'"

Not convinced

Researchers argue that other bisphenols are being used as substitutes in plastic products, based on their growing presence in the environment and in our bodies. Pinpointing the exact source is challenging because companies are not required to list them as ingredients. Plastic is one of the likely sources, but food cans, receipt paper and clothing may also contribute.

Still, Steve Hentges, a senior director at the American Chemistry Council, which represents the chemicals industry, is not convinced.

"There is little evidence or reason to believe that BPA is being replaced with other bisphenols," he said on behalf of the organization.

The 2019 Toxicology study noted that some BPA substitutes had not been studied, possibly because it was "unclear if they are chemicals in current use." The authors also noted that there was limited information on other BPA substitutes known to be in use, and stressed the need for more information about the levels of these chemicals in human populations.

Health Canada is aware of these concerns. The department confirmed in an emailed statement that "certain bisphenols have been identified for further scoping, and further information gathering is ongoing." It added that future releases of the Canadian Health Measures Survey will measure the most common BPA substitutes to assess their impact on Canadians.

BPA substitutes generally not disclosed

It is not easy for consumers to identify which plastics contain BPA substitutes, because manufacturers generally do not disclose this information on product packaging. "The only way for a concerned parent to verify is by contacting the company and asking the question," Malas said. "In many cases the company may not even know."

Identifying the substitutes is further complicated by widespread use of the BPA-free label.

"My suspicion is that the BPA-free label is marketing," said Erica Phipps, executive director of Canadian Partnership for Children's Health and Environment, an organization that advocated for BPA to be replaced with safer alternatives, in a 2010 position paper.

"It's responding to the fact that BPA has now been identified as something that we'd like to avoid exposure to. You'll see it on categories of products that never had BPA to start with."