PFAS in Drinking Water

Exposure to unsafe levels of PFAS concentrations through drinking water may result in health effects.

Per and poly-fluoroalkyl substances (PFAS) are man-made chemicals that up until 2000 had been widely used in the manufacturing of many industrial and consumer products such as paper and cardboard food packaging, insecticides, electronics, stain repellants, paints, firefighting foam and non-stick cooking surfaces.

Prior to phasing PFAS out of production around the globe, large quantities were released into the environment during manufacturing processes and are now being found in drinking water supplies near current or former manufacturing locations as well as use areas such as airports.

Potential health effects from PFAS

Exposure to unsafe levels of PFAS concentrations through drinking water may result in health effects including developmental effects to fetuses during pregnancy, cancer, liver effects, immune effects and thyroid effects.¹

In April 2024, the U.S. EPA issued the first-ever national, legally enforceable drinking water standard for PFAS in drinking water. This rule sets maximum contaminant levels (MCL’s) for PFOA at 4.0 ppt, PFOS at 4.0 ppt, PFHxS at 10 ppt, PFNA at 10 ppt, and HFPO-DA (also known as GenX) at 10 ppt. Additionally, the rule established a hazard index for mixtures containing two or more of PFHxS, PFNA, HFPO-DA, and PFBS.

What to do if there is a PFAS water advisory

Don't boil your water.² Boiling water that contains PFAS will not reduce exposure risk. Follow the advice of your municipal water authority regarding using water for drinking, cooking, bathing, dish washing, providing to pets, or filtering during the advisory.

How to reduce PFAS in drinking water

Water treatment devices Certified to NSF/ANSI Standard 53: Drinking Water Treatment Units -Health Effects, or NSF/ANSI Standard 58: Reverse Osmosis Systems are an effective way to limit exposure to PFAS.

In accordance with these standards, NSF Certification provides independent, third-party validation that:

The contaminant reduction claims for PFAS shown on the label have been validated.
The system meets strict material safety and structural integrity requirements.
The product labeling, advertising and literature are not misleading.

To make a PFAS reduction claim, a water filter must be able to reduce PFAS to below 20 parts per trillion. NSF Certified products must be retested periodically and manufacturing facilities must be inspected every year, which ensures products continue to meet all requirements.

Task groups and subtask groups serving under the NSF Drinking Water Treatment Units Joint Committee have been working to propose updates to NSF/ANSI Standard 53 and NSF/ANSI Standard 58 to align with the EPA final PFAS rule. Once this work is complete, a ballot will be submitted to incorporate the updates into Standards. Once a ballot passes both the Joint Committee and Public Health Council, the updates will be implemented.

Any proposed updates to a standard must follow the NSF Standards process that is accredited by the American National Standards Institute (ANSI) and the Standards Council of Canada (SCC). NSF/ANSI and NSF/ANSI/CAN standards are developed and revised through a public process which incorporates balanced input from industry representatives, public health and regulatory officials, certification bodies and testing labs, and users.

To find products that are certified by NSF to reduce PFAS in drinking water, see NSF’s certification listings.