PFHpS

What is PFHpS?

Perfluoroheptanesulfonic acid, or PFHpS, is a man-made chemical belonging to the PFAS family, a group of thousands of synthetic chemicals often called "forever chemicals" because they break down very slowly in the environment and in the human body. PFHpS is a longer-chain PFAS, meaning its molecular structure contains seven carbon atoms bonded to fluorine. Like other PFAS, it is extremely resistant to heat, water, and oil, which is why it has been used in industrial and consumer applications.

Where does it come from?

PFHpS can be released from industrial manufacturing facilities that produce or use fluorinated chemicals. It has also been found in connection with consumer products such as stain-resistant coatings on fabrics and carpets, water-repellent clothing, and certain food packaging materials. Firefighting foams used at airports and military bases are another known source of PFAS contamination in the environment.

Health concerns

Research on PFHpS specifically is limited compared to better-studied PFAS like PFOA or PFOS. Some animal studies have associated PFHpS with effects on the liver and thyroid, but strong human data is not yet available. Because it belongs to the broader PFAS family, researchers are actively studying whether it shares the health risks linked to other PFAS compounds in studies, such as immune system effects and hormonal disruption. If you have specific health concerns, consult a healthcare provider.

EPA standard

No federal Maximum Contaminant Level, or MCL, has been established for PFHpS by the EPA. An MCL is the legal limit for how much of a substance is allowed in public drinking water. Without a federal limit, water utilities are not required to test for or remove PFHpS.

What you can do

If PFHpS is detected in your water, consider using a certified reverse osmosis filter or an ion exchange filter, both of which research studies show can effectively reduce PFAS levels. Granular activated carbon filters may also help but are generally less effective for shorter-chain PFAS compounds. Remember that boiling water does not remove PFAS and may actually concentrate them.