Washington
What is the disclosure required for Washington?
For Washington, disclosure required is Yes; sellers of improved and unimproved residential and commercial real property must provide a disclosure statement indicating knowledge of radon gas and other substances of environmental concern; testing mandated is No; professional certification required is No state-specific requirement; 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; source re-checked 2026-10-01.
Requires sellers of improved and unimproved residential real property, as well as commercial real estate, to provide buyers with a disclosure statement providing information about carbon monoxide alarms and indicating knowledge of substances of environmental concern on the property, including radon gas, formaldehyde, asbestos, and lead-based paint.
— eli.org, retrieved 2026-08-15
- jurisdiction
- Washington
- disclosure required
- Yes; sellers of improved and unimproved residential and commercial real property must provide a disclosure statement indicating knowledge of radon gas and other substances of environmental concern.
- testing mandated
- No
- professional certification required
- No state-specific requirement
- action level pci l
- No state-specific action level; follows EPA recommended 4 pCi/L
- school testing required
- No
- statute citation
- Washington Revised Code §§ 64.06.005--.070, 19.27.074
Source
- eli.orghttps://www.eli.org/sites/default/files/files-pdf/2025%20Radon.pdf