PFAS Analyte · UCMR 5

PFHxA

Perfluorohexanoic acid

CAS 307-24-4· UCMR 5· No individual MCL set
1,700
Systems monitored
with official records
1,700
Systems with detections
100.0% detection rate
5,649
Detected samples
of 5,649 total samples
Jan 2023 – Dec 2025
Monitoring period
per UCMR 5 schedule

Detection Rate — PFHxA

Systems with any detection100.0%

1,700 of 1,700 monitored systems

Sample-level detection rate100.0%

5,649 detections across 5,649 total samples

States with Most PFHxA Detections

Water Systems with Most PFHxA Detections

Systems ranked by number of samples detected above the minimum reporting limit. Detection count reflects monitoring frequency, not concentration level.

All records are from official EPA UCMR 5 monitoring data. Detection counts reflect the number of samples where the analyte was reported above the minimum reporting limit (MRL). They are not compliance determinations and do not imply a health violation.

PFHxA at a Glance

Full NamePerfluorohexanoic acid
CAS Number307-24-4
UCMR RoundUCMR 5
EPA MCLSee mixture rule
Systems Monitored1,700
Systems Detected1,700
Detection Rate100.0%

Note

No MCL as of April 2024. Monitored under UCMR 5 for occurrence data.

EPA PFAS Drinking Water RegulationEPA UCMR 5 Source Data Back to PFAS Watchlist