California: the Toxic Mold Protection Act, and why parts of it never took effect
In 2001 California passed the Toxic Mold Protection Act (SB 732), adding Chapter 18 (§§26100 et seq.) to Division 20 of the Health and Safety Code. The Act creates mold disclosure duties for sellers, landlords, and public entities. It also directed the Department of Health Services (now CDPH) to develop permissible exposure limits and assessment standards. The disclosure duties are on the books; but they are contingent on standards that CDPH has not fully adopted, and much of the Act's operative disclosure regime remains conditional as a result.
Written by Kent Lansing, Founder & Editor·Last reviewed Verified 2026-09-08
What the Act says on paper
The Act sets mold disclosure duties across four groups:
Sellers of commercial or industrial property (§26140). Must disclose in writing when they know of mold that affects the unit or building and exceeds permissible exposure limits or poses a health threat.
Commercial/industrial landlords (§26141). Similar disclosure duty to prospective and current tenants.
Public entities (§26146). Must disclose when they know or have reasonable cause to believe chronic water intrusion, flooding, or mold exists.
Residential landlords (§26147). Must disclose to prospective and current tenants when they know or have reasonable cause to believe mold affects the unit or building.
The Act also directed CDPH to develop:
Permissible exposure limits for mold in indoor environments (§26103).
Assessment standards for health threats posed by mold presence (§26105).
Mold identification guidelines (§26120) and remediation guidelines (§26130).
Why parts of it never took effect
The load-bearing detail. §§26140(d), 26141(e), 26146(d), and 26147(e) all provide that the disclosure requirements do NOT apply until the first January 1 or July 1 that occurs at least six months after CDPH adopts standards under §§26103 and 26105. §26154 postpones enforcement of the disclosure requirements until at least six months after CDPH adopts enforcement guidelines. And §26156 provides that the chapter is implemented only to the extent CDPH determines funds are available. The permissible exposure limits under §§26103 and 26105 have not been finalized. In practical effect, the disclosure duties are on the books but the operative trigger has not fired for the parts of the Act that depend on those standards.
What this means for a California homeowner with a water or mold loss
Because much of the Act's disclosure regime is conditional, California mold coverage today is governed primarily by your policy language, the standard ISO HO-3 mold exclusion (with carrier variance), and any specific mold endorsement you have added. State statute changes the disclosure edges (particularly for landlords and public entities), not the coverage middle. Practical implications:
Read your specific homeowners policy for the mold clause and any mold endorsement. Coverage varies significantly by carrier.
If you are a tenant, the residential landlord disclosure duty under §26147 exists on paper; whether it applies to a specific building depends on whether the CDPH standards have been adopted for that building type. The California Department of Public Health website (cdph.ca.gov) is authoritative on standards status.
If you have a water loss that has become a mold loss, the sudden-vs-gradual classification and your mitigation timeline still drive the coverage answer under the standard ISO HO-3 framework — see our sudden vs gradual guide.
What the Act does NOT do
It does not cap insurer payout on mold-related losses. Unlike Texas, California has no statutory sublimit on mold coverage. The cap is whatever the policy language and endorsement provide.
It does not require insurers to offer a mold endorsement. The Act's requirements run against sellers, landlords, and public entities — not insurance carriers.
It does not create a private right of action against insurers for mold-related losses.
It does not change the standard ISO HO-3 mold exclusion. That exclusion (with carrier-specific variance) governs whether mold is covered in the first place.
How California compares
California and Texas are the two states most often mentioned in mold-coverage discussions, but for very different reasons. Texas has a TDI-administered framework that materially restricts mold coverage on standard-form homeowners policies to a sublimit unless an endorsement is added (see the Texas spoke). California has a disclosure-oriented statute (SB 732) that runs against sellers and landlords rather than insurers, and whose operative requirements are conditional on standards that were not fully adopted. Most other states have neither and rely on general policy language — see the rollup.
Sources
Cal. Toxic Mold Protection Act of 2001 (SB 732). Bill text: leginfo.legislature.ca.gov. Verified 2026-09-08.
Cal. Health & Safety Code Chapter 18 (§§26100 et seq.). Codifies the Act's provisions.
California Department of Public Health: cdph.ca.gov. Authoritative on the status of the §26103/§26105 standards.
California Department of Insurance: insurance.ca.gov. Consumer guidance on mold coverage in California homeowners policies.
Educational information, not legal or insurance advice. The Toxic Mold Protection Act's operative requirements depend on the current status of CDPH standards under §§26103 and 26105; verify with CDPH before relying on specific disclosure obligations in a landlord/tenant or sale/purchase context. Insurance coverage depends on your specific policy and any mold endorsement.