New Hampshire Department of Health and Human Services · OPLC mitigation certification
New Hampshire radon (air)
No state company roster to republish. Updated / retrieved 2026-10-03 (US/Pacific).
If you are not sure you need a pro yet, see when a DIY radon test kit is enough or how to test a home for radon.
NH DHHS does not publish a public statewide list of radon measurement or mitigation businesses to republish. This page does not invent company names, phones, licenses, or addresses to fill that gap.
Measurement: DHHS states there is no New Hampshire requirement for radon testing professionals to be certified, but recommends a nationally certified measurement professional — especially for real estate — and points to NRPP and NRSB Find a Professional.
Mitigation (air): Contractors who design or install airborne radon mitigation systems must hold current NRPP or NRSB certification under RSA 310-A:189-a / OPLC Airborne Radon Mitigation Certification. DHHS’s mitigation page likewise says New Hampshire radon-in-air mitigators are required to be nationally certified and links the same national directories. Filter by measurement vs. mitigation, then re-check the credential before hiring.
What DHHS and OPLC say homeowners can do
- Radon is a gas you cannot see, smell, or taste. It comes from uranium breaking down in rock and soil (New Hampshire’s granite is often cited) and can enter a home through the foundation. DHHS also discusses radon that can enter from private-well water; this index page covers indoor air only.
- DHHS instructional materials on the testing page state that about 1 in 3 New Hampshire homes have elevated radon test levels. Levels vary — the only way to know is to test.
- EPA’s guideline remains 4.0 pCi/L. DHHS cites EPA’s recommendation to reduce radon when airborne levels are at or above that action level.
- Short-term air tests (about 2–90 days) and long-term tests (more than 91 days, up to a year) can measure radon. DHHS notes radon often runs higher in colder months when homes are closed and heated.
- Free short-term test kits for New Hampshire residents: request at https://states.aelabs.com/#/nh (linked from the DHHS testing page / kit video).
- DHHS runs a library loan project for handheld continuous radon monitors. Participating libraries are listed on the DHHS Testing for Radon page — this index does not invent library names.
- For mitigation system design/install (air), verify current NRPP or NRSB certification. OPLC certification questions: 7 Eagle Square, Concord, NH 03301; 603-271-2152 (as printed on the OPLC page). Program questions: see the NH DHHS Radon Program hub (hub contact beyond Relay NH TDD was not clearly printed when retrieved).
Official sources
- NH DHHS — Radon Program hub (retrieved 2026-10-03; primary hub)
- NH DHHS — Testing for Radon (retrieved 2026-10-03; measurement guidance, free kits, library loan)
- NH DHHS — Fixing Radon: Mitigation (retrieved 2026-10-03)
- OPLC — Airborne Radon Mitigation Certification (RSA 310-A:189-a; retrieved 2026-10-03)
- NRPP Find a Pro (linked from DHHS/OPLC)
- NRSB Find a Professional (linked from DHHS/OPLC)
- Free short-term kit request (NH residents)
- U.S. EPA Radon
This index does not rank contractors or take referral fees. No Amazon kit links on this state page. This page covers indoor air only, not well water.