PFHxA
Overview
Perfluorohexanoic acid, a short-chain PFAS with no federal drinking-water limit. Widely used as a replacement for longer-chain PFAS that were phased out, and now widely detected.
In Florida, PFHxA was found in 109 community water systems serving about 9,404,420 people. Nobody has set a legal limit for it, so no reading here counts as an exceedance and no utility is required to do anything about it.
Where it comes from: Replacement chemistry for phased-out PFAS; textile and paper coatings; firefighting foam.
The standards
Enforceable. A utility must stay at or under this.
Health-based, not enforceable. Often lower than the limit, sometimes zero.
EPA's Integrated Risk Information System published a final toxicological review of perfluorohexanoic acid (PFHxA) in April 2023, the only short-chain perfluorocarboxylic acid it has assessed. Florida Water Report applies that assessment to the short-chain acids that have no assessment of their own. Source: EPA IRIS Toxicological Review of Perfluorohexanoic Acid (PFHxA) and Related Salts, EPA/635/R-23/027F, April 2023.
Health effects the EPA associates with it: No federal drinking-water limit has been set. EPA links PFAS exposure generally to decreased immune response, increased cholesterol, and developmental effects.
The health goal is set on health alone. The legal limit is set as close to it as is technically and economically feasible, so treatment cost and available technology are written into the number a utility is measured against. A system at or under the limit is meeting the standard it is required to meet. Both numbers are shown so the distance between them is visible.
What removes it
Reverse osmosis or anion exchange. As a short-chain replacement compound it breaks through carbon earlier than the PFAS most filters are rated for.
Treatment guidance describes the methods generally used for this contaminant. What your own tap actually carries depends on your plumbing and your service line as much as on the utility, which is what a test at the house tells you and an annual report cannot.
Where in Florida
Highest reported levels
Showing the 25 highest of 109 systems that reported PFHxA.
Data Sources
These figures describe water as delivered by each utility, not what your home’s plumbing adds after it arrives. Informational; not a substitute for testing your own tap.