GenX (HFPO-DA)

Category: pfas

Written by WaterFilterMatch Editorial TeamSeptember 2026

EPA MCL

10 ppt

Status

EPA Regulated

NSF Standard

NSF/ANSI 53, NSF/ANSI 58

Health Effects

Associated with liver toxicity, kidney effects, developmental toxicity, and cancer in animal studies. Developed as a replacement for PFOA but raises similar health concerns.

Source: EPA National Primary Drinking Water Regulations

Where It Comes From

Short-chain PFAS compound used as a replacement for PFOA in fluoropolymer manufacturing. A processing aid in production of non-stick and fluoropolymer products.

Where It's Commonly Found

Communities near fluorochemical manufacturing plants, notably in North Carolina (Fayetteville area) and other industrial zones. Less widespread than PFOA/PFOS but increasingly detected.

Detected in hundreds of public water systems under UCMR 5 monitoring. Note: in May 2026 EPA formally proposed rescinding the GenX MCL while keeping the PFOA/PFOS limits in place; the public comment period closed July 20, 2026, and no final rule has been issued, so the 2024 limit remains legally in effect while litigation over the rule continues.