PFHxS · US EPA (National Primary Drinking Water Regulations)
For PFHxS, regulator is US EPA (National Primary Drinking Water Regulations); limit is disputed: 0.00001 per epa.gov, 10 ppt per epa.gov; unit is disputed: mg/L per epa.gov, ppt per epa.gov; limit type is MCL (Maximum Contaminant Level), recorded from its source on 2026-08-06.
- Contaminant
- PFHxS verified
- Regulator
- US EPA (National Primary Drinking Water Regulations) our reading
- Limit
- 0.00001 the source states this two ways
- Unit
- mg/L the source states this two ways
- Limit type
- MCL (Maximum Contaminant Level) our reading
Values marked our reading are our classification of what the source says — the source does not print them in those words. The quote below is the evidence for each one; judge it yourself.
What the source says
PFHxS | 0.00001 | 0.00001
— epa.gov, retrieved 2026-08-06
The source states this two ways
The same publisher states this differently in more than one place. Each version is reproduced with the page it came from — deciding between them is yours, not ours.
Limit
epa.gov says limit is 0.00001, as of 2026-08-06.
PFHxS | 0.00001 | 0.00001
https://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations
epa.gov says limit is 10 ppt, as of 2026-08-06.
PFHxS | 10 ppt | 10 ppt
https://www.epa.gov/sdwa/and-polyfluoroalkyl-substances-pfas
Unit
epa.gov says unit is mg/L, as of 2026-08-06.
PFHxS | 0.00001 | 0.00001
https://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations
epa.gov says unit is ppt, as of 2026-08-06.
PFHxS | 10 ppt | 10 ppt
https://www.epa.gov/sdwa/and-polyfluoroalkyl-substances-pfas