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November 9, 2021

Chemical Watch Article “Stakeholders see room for improvement in US EPA’s PFAS categorization” Features Comments by Richard E. Engler, Ph.D.

Bergeson & Campbell, P.C.

On November 9, 2021, Richard E. Engler, Ph.D., Director of Chemistry, Bergeson & Campbell, P.C. (B&C®), was quoted by Chemical Watch regarding the U.S. Environmental Protection Agency’s (EPA) classification of per- and polyfluoroalkyl substances (PFASs) for company-funded testing under the Toxic Substances Control Act (TSCA).

According to Richard Engler, director of chemistry for law firm Bergeson & Campbell, the agency has “come down somewhere in the middle” between examining the huge variety of PFASs as one class and as single compounds, avoiding over- or under-clustering.

He said the scheme is “entirely appropriate” because it relies on read-across to leverage partial data to evaluate multiple structurally comparable substances, enables the agency to zero in on problem groups like surfactants and limits vertebrate testing.

One potential enhancement would be accounting for degradation product hazards by looking at the pendant group – or side chain – hanging off each PFAS backbone, Dr Engler told Chemical Watch. When a fluorinated side chain breaks off, he said, it can persist in the environment and pose risks.  

“The hazard of the degradation product is going to be whatever the length of the group is,” Dr Engler said. “You can lump a lot of those polymers together based on the length of the pendant group, rather than the properties of the backbone.”

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