US EPA

EPA has finalized the IRIS Toxicological Review of Perfluorohexanoic Acid (PFHxA) and Related Salts. This assessment addresses the potential cancer and noncancer human health effects from exposure to perfluorohexanoic acid and related salts. EPA’s program and regional offices may use this assessment to inform decisions to protect human health.

Perfluorohexanoic Acid (PFHxA) and its related salts are members of the group of per and polyfluoroalkyl substances (PFAS). Concerns about PFHxA and other PFAS stem from the resistance of these compounds to hydrolysis, photolysis, and biodegradation, which leads to their persistence in the environment. PFAS are not naturally occurring in the environment; they are man-made compounds that have been used widely over the past several decades in consumer products and industrial applications because of their resistance to heat, oil, stains, grease, and water.

PFHxA is a breakdown product of other PFAS that are used in stain-resistant fabrics, paper food packaging, and carpets; it is also used for manufacturing photographic film, and it is used as a substitute for longer chain perfluoroalkyl carboxylic acids (PFCAs) in consumer products. PFHxA has been found to accumulate in agricultural crops and has been detected in household dust, soils, food products, and surface, ground, and drinking water.

As such, exposure is possible via inhalation of indoor or outdoor air, ingestion of drinking water and food, and dermal contact with PFHxA-containing products.

EPA is undertaking an update of the Integrated Risk Information System (IRIS) health assessment for PFHxA and it's related salts. The outcome of this project is an IRIS Toxicological Review and Executive Summary for PFHxA that will be entered into the IRIS database.

U.S. EPA. Toxicological Review of Perfluorohexanoic Acid (PFHxA) and Related Salts (Final Report, 2023). U.S. Environmental Protection Agency, Washington, DC, EPA/635/R-23/027F, 2023.