Canada contemplates restrictions on well-loved stain repellents
After Canada placed the world’s first temporary ban on a few fluorotelomer polymers, it considers action on the entire chemical class.
Widely used stain repellants that keep fast-food grease off clothes and nasty stains off carpets could be on their way out in Canada, given two recent actions.
Last December, the country announced its intention to craft a plan to evaluate, regulate, restrict, or ban the entire class of chemical compounds known as fluorotelomer polymers and their precursors. Officials with Environment Canada (EC), the country’s environmental regulator, say that they believe fluorotelomer polymers contribute to widespread environmental contamination by perfluorocarboxylates (PFCAs), which are persistent and bioaccumulative and have been linked to cancer and developmental effects in animal experiments.
EC also notes that the properties of PFCAs with long chains (carbon–fluorine chains that contain nine or more carbons) meet the criteria for persistent organic pollutants (POPs) under the international Stockholm Convention on Persistent Organic Pollutants.
Canada became the first country to regulate fluorotelomer polymers in 2004 when it issued temporary two-year bans on four of the chemicals. In the meantime, the governments of other nations, including the U.S. and the EU, are investigating them for possible environmental and human health effects.
Canada’s current temporary bans will begin to expire in June unless they are made permanent by regulation, according to EC officials. Their plan to investigate fluorotelomer polymers may lead to permanent bans and could encompass chemicals already in use and new substances of this type. EC officials say they will meet on February 6 and 7 to begin crafting their plan.
These recent actions open the door for an aggressive approach to all of these chemicals, the officials add. “The presumption that the recent Canadian action is only one of the first in a series of regulatory initiatives seems most likely,” says Ethel Forsberg, director general of KEM, the Swedish Chemicals Inspectorate. In 2004, Sweden nominated a related substance, perfluorooctansulfonate (PFOS), to be included in the treaty.
At the heart of the Canadian activity are risk assessments released by EC officials in December that justify the government’s existing temporary bans on several fluorotelomer polymers. The assessments focus attention on a relatively unexplored facet of these chemicals’ environmental behavior: the possibility that these polymers could be a slow but steady source of human and environmental exposure to PFCAs, which are being found in the blood of Arctic animals far away from any sources and in the blood of humans the world over. The scientists suspect that microbes or even hydrolysis reactions can break some of the fluorotelomer polymers’ chemical linkages and release chemical compounds that can degrade to PFCAs.
These assessments note that long-chain PFCAs meet the criteria for POPs as defined by the international Stockholm Convention. The treaty, which went into force in May 2004, banned production of 12 notorious pollutants, including DDT and PCBs. The treaty also specifies provisions for nominating additional POPs to be either banned or controlled. (Environ. Sci. Tech. 2004, 38 (9), 157A).
The Canadian assessments offer “a coarse, sweeping review,” says U.S. EPA scientist John Washington, who heads an EPA experimental project to look for linkage breakage in fluorotelomer polymers. “But the review represents one set of opinions that knowledgeable people have about the issue,” he says.
EPA staff are currently finalizing a risk assessment for PFOA, the most widely studied PFCA, which has been linked to cancer and other adverse effects in animal experiments. EPA officials are concerned about the possibility of fluoropolymer linkage breakage because agency scientists think it might help solve the puzzle of how people are exposed to PFOA, Washington says.
Fluorotelomer polymers are in wide use and have been for decades, so even if the rate of linkage breakage was slow, the phenomenon could still account for a significant contribution to the environment, he told attendees at the Society of Environmental Toxicology and Chemistry meeting in November in Baltimore, Md.
However, at the same meeting, DuPont scientist William Berti and Robert Buck presented preliminary results from their own short-term biodegradation experiments, which they interpreted to show that biodegradation does not occur. DuPont spokesperson Dan Turner did not return calls for this story.
Also in December, EPA officials announced that DuPont would spend $5 million over 3 years to investigate whether 9 of its perfluorinated chemicals biodegrade. The pledge is part of a record $16.5 million settlement between EPA and DuPont over accusations that the chemical company broke laws by failing to report to EPA information about health effects of PFOA and exposure levels near fluorochemical manufacturing plants. EPA won’t release the names of these chemicals, an agency spokesperson says, because they are considered to be confidential business information.
