Agrochemical toxicologist urges targeted action on clearly harmful PFAS, warns broad definitions would sweep in medicines and pesticides

Dr. Pam Bridal, agrochemical toxicologist with the Agency of Agriculture, Food Markets, told a legislative panel that regulators should target a small number of PFAS with clear evidence of harm rather than adopt broad, structure-based definitions that would sweep in millions of substances.

Bridal said the pesticide regulatory system evaluates chemicals one by one and that ‘‘the harmful PFAS are not allowed in pesticides,’’ a point she tied to pesticide registration and reporting obligations under federal law. She urged lawmakers to prioritize rapid action on a limited set of PFAS with well-documented effects instead of spending time debating an expansive structural definition.

Why it matters: States and federal agencies are using different PFAS definitions — the OECD 'fully fluorinated carbon' formulation, EPA/TSCA definitions and several state approaches vary in wording and scope. Those differences produce large disparities in lists of chemicals described as PFAS: Dr. Bridal cited figures discussed in the panel ranging from roughly 1,200 commonly used PFAS to millions of possible structures under the broadest structural…