# New Hampshire — State Residential Radon Disclosure, Testing, and Certification Requirements

For New Hampshire, disclosure required is Yes; prior to executing a contract for sale, sellers must provide buyers a radon notification statement about radon gas and testing; testing mandated is No; professional certification required is Yes; those who design or install radon mitigation systems must be certified with the National Radon Proficiency Program or the National Radon Safety Board; action level pci l is No state-specific action level; follows EPA recommended 4 pCi/L; school testing required is No, recorded from its source on 2026-08-15.

- **jurisdiction:** New Hampshire _(verified: appears in the quote below)_
- **disclosure required:** Yes; prior to executing a contract for sale, sellers must provide buyers a radon notification statement about radon gas and testing. _(verified: appears in the quote below)_
- **testing mandated:** No
- **professional certification required:** Yes; those who design or install radon mitigation systems must be certified with the National Radon Proficiency Program or the National Radon Safety Board.
- **action level pci l:** No state-specific action level; follows EPA recommended 4 pCi/L
- **school testing required:** No
- **statute citation:** New Hampshire Revised Statutes §§ 477:4-a, 310-A:189-a, 125:9

## What the source says

> Requires that prior to executing a contract for the sale of real property, the seller must provide to buyer the following radon notification statement: "Radon gas, the product of decay of radioactive materials in rock may be found in some areas of New Hampshire. This gas may pass into a structure through the ground or through water from a deep well.

## Source

- https://www.eli.org/sites/default/files/files-pdf/2025%20Radon.pdf

Last verified: 2026-08-15. Review by: 2027-08-15.
Part of [State Residential Radon Disclosure, Testing, and Certification Requirements](https://referencesource.org/state-radon-disclosure-requirements/).