Perfluorohexanoic acid

Perfluorohexanoic acid (PFHxA) is a fluorinated carboxylic acid derivative of hexanoic acid. Fluorinated polymers with six carbon or less commonly degrade into perfluorohexanoic acid.

Perfluorohexanoic acid does not seem to persistently bioaccumulate in the manner of many other PFAS. For example, in a study sponsored by the Swedish EPA, Swedish ski wax technicians, who have high PFAS exposure, did not have significantly higher levels of PFHxA in their blood samples when compared to the general population median for their age groups, even while having concentrations of other PFAS, like PFOA, up to 44 times higher than the general population.

In 2020 Michigan adopted drinking water standards for five previously unregulated PFAS compounds including PFHxA which has a maximum contaminant level (MCL) of 400 parts per billion (ppb).