FRD-903

FRD-903 (also known as hexafluoropropylene oxide dimer acid, HFPO-DA, and 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoic acid) is a chemical compound that is among the class of per- and polyfluoroalkyl substances (PFASs). More specifically, this synthetic petrochemical is also described as a perfluoroalkyl ether carboxylic acid (PFECA) and a Fluorointermediate. It is not biodegradable and is not hydrolyzed by water.

Production
The production process involves 2 molecules of Hexafluoropropylene oxide (HFPO) to produce Hexafluoropropylene oxide dimer acid fluoride (FRD-903), The ammonium salt of FRD-903 is FRD-902 (ammonium (2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoate)), which is the specific chemical which Chemours has trademarked as part of GenX process. FRD-903 is used as an aid within the manufacturing process for fluoropolymers by reducing the surface tension in the process, allowing polymer particles to increase in size. The process is completed with chemical treatment or heating to remove the FRD-903 from the final polymer product. It can then be recovered for re-use within the process.

Drinking water
In 2020 Michigan adopted drinking water standards for 5 previously unregulated PFAS compounds including HFPO-DA which has a maximum contaminant level (MCL) of 370 parts per trillion (ppt).

In March 2023, the EPA announced drinking water standards for several PFAS chemicals, which included FRD-903.