In California, it is required by law for sellers of residential properties with four units or less to provide a Real Estate Transfer Disclosure Statement (TDS) to potential buyers. The TDS is a detailed document that informs buyers about any defects or conditions the seller is aware of, as mandated by the state. This includes substances, products, or construction materials, such as lead paint or asbestos, that may pose a hazard to buyers.

Additionally, sellers have the option to provide the booklet "Environmental Hazards: "A Guide for Homeowners, Homebuyers, Landlords, and Tenants" created by the California Department of Real Estate, which contains the necessary information required by the state and relieves the seller from further disclosure obligations regarding property hazards. However, if the seller is aware of asbestos contamination or other hazardous materials, they must explicitly disclose this information.

For buildings constructed before 1979, the California Health & Safety Code requires a specific declaration of any asbestos-containing materials, regardless of their prevalence or condition. It is generally recommended that sellers in California disclose the possibility of asbestos presence, even if not legally obligated, to avoid potential legal and financial liabilities in the future.