Question 1

What is Perfluorooctanoic Acid?

Accepted Answer

Perfluorooctanoic Acid (PFOA) is a per- and polyfluoroalkyl substance (PFAS) – a synthetic chemical used in manufacturing, firefighting foam, and consumer products. It persists indefinitely in water and the human body.

Question 2

Is PFOA in my drinking water?

Accepted Answer

EPA UCMR5 testing (2023-2025) monitors PFOA at 6,800+ US water systems. Enter your ZIP code at KnowYourExposure.com to see if PFOA has been detected in your specific utility.

Question 3

What is the EPA limit for PFOA?

Accepted Answer

The EPA drinking water limit for PFOA is 4 parts per trillion (ppt). Utilities have until 2029 to reduce levels below this threshold under the 2024 PFAS Rule.

Question 4

What are the health effects of PFOA?

Accepted Answer

PFOA exposure has been linked to: Kidney cancer, Testicular cancer, Thyroid disease. Long-term exposure increases risks even at low doses.

Question 5

How do I remove PFOA from my water?

Accepted Answer

Certified reverse osmosis systems remove 90%+ of most PFAS including PFOA. Activated carbon and ion exchange filters also work. Boiling does NOT remove PFAS – it concentrates them.

Question 6

What is the CAS number for Perfluorooctanoic Acid?

Accepted Answer

The CAS Registry Number for Perfluorooctanoic Acid is 335-67-1.

PFOA: Health Effects, EPA Limits & Sources (2026)