EPA legal limit
No federal limit
Maximum Contaminant Level
EWG health guideline
No guideline
Science-based, stricter target
Health effects
PFHpS research is less extensive than for PFHxS or PFOS. Its seven-carbon chain is expected to produce bioaccumulation and toxicity between PFHxS (six-carbon, regulated) and PFOS (eight-carbon, regulated). Studies show thyroid and immune effects consistent with other long-chain sulfonates.
Where it comes from
Industrial use as a surfactant and PFOS replacement. Found in water contaminated by firefighting foam (AFFF), metal plating operations, and fluoropolymer manufacturing. Often co-detected with PFHxS and PFOS.
How it's regulated
No federal EPA MCL. No EPA Lifetime Health Advisory established as of 2025. Monitored under UCMR5. No EWG health guideline established due to limited toxicological data.
How to filter pfhps
Not all filters address pfhps. Look for independently certified filters—NSF International certification means the removal claim has been independently verified.
Frequently asked questions
What is pfhps?
PFHpS is a seven-carbon sulfonic acid PFAS. It bridges short-chain and long-chain sulfonates in terms of both structure and expected behaviour in the environment. PFHpS is detected in UCMR5 monitoring and shares contamination sources with PFHxS and PFOS.
What are the health effects of pfhps?
PFHpS research is less extensive than for PFHxS or PFOS. Its seven-carbon chain is expected to produce bioaccumulation and toxicity between PFHxS (six-carbon, regulated) and PFOS (eight-carbon, regulated). Studies show thyroid and immune effects consistent with other long-chain sulfonates.
Is pfhps regulated in drinking water?
No federal EPA MCL. No EPA Lifetime Health Advisory established as of 2025. Monitored under UCMR5. No EWG health guideline established due to limited toxicological data.
Where does pfhps come from?
Industrial use as a surfactant and PFOS replacement. Found in water contaminated by firefighting foam (AFFF), metal plating operations, and fluoropolymer manufacturing. Often co-detected with PFHxS and PFOS.
How do I remove pfhps from tap water?
The most effective methods for removing pfhps are: Reverse osmosis (RO), NSF 58 certified RO system, Activated carbon block filter. Look for NSF-certified systems—independent certification confirms removal claims have been verified.
Is pfhps in your water?
Enter your ZIP code to see the measured level in your specific utility.