Illinois
For Illinois, disclosure required is Yes; sellers must disclose known elevated radon levels and provide buyers a state-developed pamphlet on radon testing and a general warning statement. Landlords must also disclose radon hazards to tenants; testing mandated is Yes; licensed day care centers and homes must test for radon at least once every three years. All new residential construction must include passive radon-resistant construction techniques; professional certification required is Yes; state licensing required for persons selling radon detection devices, performing radon detection, or performing radon reduction services; action level pci l is State action level referenced but defers to EPA recommended 4 pCi/L; school testing required is Yes; recommends that occupied school buildings be tested every five years for radon, with reporting to the Board of Education, recorded from its source on 2026-08-15.
- jurisdiction
- Illinois
- disclosure required
- Yes; sellers must disclose known elevated radon levels and provide buyers a state-developed pamphlet on radon testing and a general warning statement. Landlords must also disclose radon hazards to tenants.
- testing mandated
- Yes; licensed day care centers and homes must test for radon at least once every three years. All new residential construction must include passive radon-resistant construction techniques.
- professional certification required
- Yes; state licensing required for persons selling radon detection devices, performing radon detection, or performing radon reduction services.
- action level pci l
- State action level referenced but defers to EPA recommended 4 pCi/L
- school testing required
- Yes; recommends that occupied school buildings be tested every five years for radon, with reporting to the Board of Education.
- statute citation
- Illinois Compiled Statutes Ch. 420, §§ 44/1--90, 46/1--25, 52/1 et seq.; Ch. 765, §§ 77/1--65; Ch. 225, § 10/5.8; Ch. 105, § 5/10-20.48
What the source says
Requires sellers to disclose known elevated radon levels in the home and to provide buyers a state- developed pamphlet on radon testing and a general warning statement recommending radon testing prior to all home purchases and mitigation of elevated levels.
— eli.org, retrieved 2026-08-15
Source
- eli.orghttps://www.eli.org/sites/default/files/files-pdf/2025%20Radon.pdf