pfasUCMR5Unregulated by EPA

PFPeA (perfluoropentanoic acid)

Reviewed for accuracy against EPA data and peer-reviewed literature · Updated May 2026

PFPeA is a five-carbon carboxylic acid PFAS detected in water serving 101 million people across 46 states in UCMR5 monitoring — the second most widely detected PFAS after PFHxA. Like other short-chain PFAS, it has replaced longer-chain compounds in many industrial applications and is highly mobile in water.

CAS 2706-90-3

EPA legal limit

No federal limit

Maximum Contaminant Level

EWG health guideline

3 ppt

Science-based, stricter target

Health effects

PFPeA research is less extensive than for long-chain PFAS. Available animal studies show liver and kidney effects. Its shorter carbon chain means less bioaccumulation than PFOA or PFOS, but its ubiquitous detection in drinking water indicates significant ongoing dietary exposure across the US population.

Where it comes from

Industrial replacement for longer-chain PFAS in surface coatings, metal plating, and processing aids. Found alongside other short-chain PFAS in water supplies downstream from industrial sources and in agricultural areas with PFAS-containing biosolids application.

How it's regulated

No federal EPA MCL. Monitored under UCMR5. No EPA Lifetime Health Advisory established as of 2025. EWG health guideline: 3 ppt, based on a precautionary approach to short-chain PFAS with limited toxicological data.

How to filter pfpea

Not all filters address pfpea. Look for independently certified filters — NSF International certification means the removal claim has been independently verified.

Reverse osmosis (RO)NSF 58
NSF 58 certified RO system
Activated carbon block filterNSF 53

Frequently asked questions

What is pfpea?

PFPeA is a five-carbon carboxylic acid PFAS detected in water serving 101 million people across 46 states in UCMR5 monitoring — the second most widely detected PFAS after PFHxA. Like other short-chain PFAS, it has replaced longer-chain compounds in many industrial applications and is highly mobile in water.

What are the health effects of pfpea?

PFPeA research is less extensive than for long-chain PFAS. Available animal studies show liver and kidney effects. Its shorter carbon chain means less bioaccumulation than PFOA or PFOS, but its ubiquitous detection in drinking water indicates significant ongoing dietary exposure across the US population.

Is pfpea regulated in drinking water?

No federal EPA MCL. Monitored under UCMR5. No EPA Lifetime Health Advisory established as of 2025. EWG health guideline: 3 ppt, based on a precautionary approach to short-chain PFAS with limited toxicological data.

Where does pfpea come from?

Industrial replacement for longer-chain PFAS in surface coatings, metal plating, and processing aids. Found alongside other short-chain PFAS in water supplies downstream from industrial sources and in agricultural areas with PFAS-containing biosolids application.

How do I remove pfpea from tap water?

The most effective methods for removing pfpea 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 pfpea in your water?

Enter your ZIP code to see the measured level in your specific utility.