PFOA · US EPA (National Primary Drinking Water Regulations)
For PFOA, regulator is US EPA (National Primary Drinking Water Regulations); limit is disputed: 0.0000040 per epa.gov, 4.0 parts per trillion (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
- PFOA verified
- Regulator
- US EPA (National Primary Drinking Water Regulations) our reading
- Limit
- 0.0000040 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
PFOA | zero | 0.0000040
— 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 0.0000040, as of 2026-08-06.
PFOA | zero | 0.0000040
https://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations
epa.gov says limit is 4.0 parts per trillion (ppt), as of 2026-08-06.
PFOA | Zero | 4.0 parts per trillion (ppt) (also expressed as ng/L)
https://www.epa.gov/sdwa/and-polyfluoroalkyl-substances-pfas
Unit
epa.gov says unit is mg/L, as of 2026-08-06.
PFOA | zero | 0.0000040
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.
PFOA | Zero | 4.0 parts per trillion (ppt) (also expressed as ng/L)
https://www.epa.gov/sdwa/and-polyfluoroalkyl-substances-pfas