Health & Saf. Code, § 105430

(a) If model construction standards and techniques for controlling radon levels within new buildings are developed by the United States Environmental Protection Agency, the State Department of Health Services may adopt the standards and incorporate them into any radon assessment and mitigation plan which may be completed by the department and which becomes operative after January 1, 1990, unless the Department of Housing and Community Development adopts radon mitigation building standards, in which case the State Department of Health Services shall adopt no standards other than the standards adopted by the Department of Housing and Community Development.

Any radon assessment and mitigation plan shall include appropriate measures designed to detect, avoid, or dissipate dangerous levels of radon gas at potential building sites or during construction of new residential buildings in areas affected by radon. Any of those measures shall be appropriately delineated so as to apply only to certain at-risk buildings and geographic areas, and the plan shall specify construction projects, building characteristics, and geographical areas to which the measures apply, to assure ease of compliance and consistency with the findings and assessment of the United States Environmental Protection Agency regarding radon risks. The plan may include reasonable provisions for testing and detection of radon at potential building sites as well as measures to provide for the appropriate radon-dissipating ventilation and insulation of new residential construction consistent with prevailing techniques.

(b) If regulations are adopted by the department to implement any radon assessment and mitigation plan completed by the department after January 1, 1990, no city, county, or other governmental agency may issue a permit to construct any building subject to state department regulation to any applicant who does not first comply with testing or building standards which may be implemented pursuant to this section.

(c) Any building standards which may be adopted pursuant to this section shall become effective as provided by Section 17958.

(d) In developing regulations pursuant to this section, the state department shall consider the methods and techniques which can provide an adequate level of safety at the lowest cost in order to reduce the impact on housing prices.

(e) Subdivisions (a) to (d), inclusive, shall only become operative if federal funds are available to the department for the purposes specified in this section, as determined by the department.