Date: May 20, 2026
Two proposed rules in the Federal Register would give systems with federal exemptions until 2031 to meet the PFOA and PFOS limits and would remove the limits for PFHxS, PFNA, HFPO-DA and the hazard-index mixture. Monitoring and reporting timeframes from the 2024 rule were left unchanged; comments closed July 20, 2026.
What it means for calibration
The list of regulated PFAS may shrink, but the monitoring timelines did not change. PFOA and PFOS calibrations still need to hold at the low end of the range.
Source: www.epa.gov
Part of the WLTR Standards Hub. This is a plain-language summary, not regulatory advice. Confirm requirements with your accrediting body. Questions or a different read on this change? Leave a comment below.