EPA Eyes New Hampshire Air Definition Overhaul
Published Date: 11/20/2025
Proposed Rule
Summary
The EPA wants to update New Hampshire’s air pollution rules to match federal standards better. This change affects businesses that need air permits by clarifying what counts as hazardous or regulated air pollutants. You’ve got until December 22, 2025, to share your thoughts, and these updates won’t cost anyone extra but will keep the air cleaner and safer.
Analyzed Economic Effects
2 provisions identified: 1 benefits, 1 costs, 0 mixed.
NH Title V Permits Must Cover New HAPs
If your business in New Hampshire needs a Clean Air Act title V operating permit, New Hampshire revised its definitions so the permit program must incorporate all hazardous air pollutants listed under CAA section 112(b), including the 2022 addition of 1-bromopropane (1-BP). The state submitted the revised definitions to EPA on June 12, 2025 (with a supplemental letter on July 31, 2025); the federal proposal would approve those revisions so permit calculations must reflect the full HAP list (the list currently contains 189 HAPs).
Federal Alignment Aims to Protect Public Health
New Hampshire's revised definitions align with federal Clean Air Act rules so the state's title V permit program will automatically incorporate current and future hazardous air pollutants listed under CAA section 112(b). That alignment (including adding 1-bromopropane) is intended to ensure hazardous air pollutants are regulated under state permits, which supports cleaner and safer air for people in New Hampshire.
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Key Dates
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