EWG's Tap Water Database — 2021 UPDATE


Perfluorohexanoic Acid (PFHxA)

Windham Terrace

Perfluorohexanoic acid is a member of a group of perfluorinated chemicals used in many consumer products. Perfluorinated chemicals can cause serious health effects, including cancer, endocrine disruption, accelerated puberty, liver and immune system damage, and thyroid changes. These chemicals are persistent in the environment and they accumulate in people. Click here to read more about perfluorinated chemicals.





Samples exceeding legal limit (MCL)


Samples exceeding
health guidelines

Testing results - average by year

YearAverage resultSamples takenDetectionsRange of results
20175.00 ppt115.00 ppt
20183.10 ppt113.10 ppt
20193.55 ppt113.55 ppt

ppt = parts per trillion

State and national drinking water standards and health guidelines

EWG Health Guideline 1 ppt

The EWG Health Guideline of 1 ppt for perfluorohexanoic acid was defined by EWG based on studies by Phillipe Grandjean of Harvard University and many other independent researchers who found reduced effectiveness of vaccines and adverse impacts on mammary gland development from exposure to PFOA and PFOS, the two PFAS most widely detected in drinking water. This health guideline protects against applies to the entire class of PFAS detected in water.

ppt = parts per trillion

All test results

Date Lab ID Result
2017-07-201707218-015.00 ppt
2018-04-09GLL0433.10 ppt
2019-10-071910-00993-0013.55 ppt