# District of Columbia — State Residential Radon Disclosure, Testing, and Certification Requirements

For District of Columbia, disclosure required is Yes; sellers of property containing up to four dwelling units must provide a real property disclosure statement including information about radon, asbestos, lead-based paint, and formaldehyde; testing mandated is Yes; D.C. Dept. of General Services must assess D.C.-owned buildings including schools for radon and other IAQ risks; professional certification required is Yes; persons conducting radon screening, testing, or mitigation for a fee must be certified by the National Radon Proficiency Program or the National Radon Safety Board; action level pci l is No D.C.-specific action level; follows EPA recommended 4 pCi/L; school testing required is Yes; D.C.-owned buildings including schools must be assessed for radon, recorded from its source on 2026-08-15.

- **jurisdiction:** District of Columbia
- **disclosure required:** Yes; sellers of property containing up to four dwelling units must provide a real property disclosure statement including information about radon, asbestos, lead-based paint, and formaldehyde. _(verified: appears in the quote below)_
- **testing mandated:** Yes; D.C. Dept. of General Services must assess D.C.-owned buildings including schools for radon and other IAQ risks.
- **professional certification required:** Yes; persons conducting radon screening, testing, or mitigation for a fee must be certified by the National Radon Proficiency Program or the National Radon Safety Board.
- **action level pci l:** No D.C.-specific action level; follows EPA recommended 4 pCi/L
- **school testing required:** Yes; D.C.-owned buildings including schools must be assessed for radon.
- **statute citation:** District of Columbia Code §§ 42-1301--1311, 28-4201--4203, 10-712

## What the source says

> Requires sellers of property containing up to four dwelling units to provide to purchasers a real property disclosure statement on a form approved by the Mayor. Regulation adopting Seller's Disclosure Statement (17 D.C. Mun. Regs. 2708) requires information about sellers' knowledge of environmental problems on the property, including radon, asbestos, lead-based paint, and formaldehyde

## 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/).