[…] A new joint report from the two NGOs has found that 37 active substances currently approved for use in pesticides are PFAS. That equates to 12 per cent of all approved synthetic substances. […]

  • ornery_chemist
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    1 year ago

    I’ve got a technical bone to pick with the article. It seems that the article is referring to the active ingredients in pesticides themselves (instead of, say, some kind of perfluorinated surfactant additive). The active ingredients of the two pesticides called out in the article (Flufenacet and Diflufenican) each contain a -CF3 unit, and so they are PFASs themselves. The molecular structures are published, so saying “PFASs SHOCKINGLY discovered in pesticides” is a bit like saying “metal SHOCKINGLY discovered in food additives” in reference to table salt. Now admittedly table salt is pretty benign and pesticides are decidedly not, at least to certain organisms.

    As a side note, fluorinated functional groups (including polyfluoroalkyls, the “PFA” of PFAS) are often incorporated into bioactive molecules to increase metabolic stability or to change properties like lipophilicity and acidity/basicity. This, even though fluorinated organic molecules are extremely rare in nature. You find them all the time in drugs, including well-known ones like fluoxetine (Prozac) and celecoxib (Celebrex). Given the huge space of possible structures that could contain such a group, I am skeptical that all polyfluoroalkyl-containing molecules (PFASs) are as bad as e.g., PFOS wrt stability and toxicity; however, given their greater tendency to stick around relative to their non-fluorinated counterparts, regulation is likely prudent, especially for higher-volume chemicals like coatings, surfactants, and yes, pesticides.