CA Health & Safety Code § 39658 (2021)
2021 California Code|Health and Safety Code - HSC|DIVISION 26 - AIR RESOURCES|PART 2 - STATE AIR RESOURCES BOARD|CHAPTER 3.5 - Toxic Air Contaminants|ARTICLE 2.5 - Coordination With the Federal Act|Section 39658.

39658.  The state board shall establish airborne toxic control measures for toxic air contaminants in accordance with all of the following:(a)  If a substance is identified as a toxic air contaminant pursuant to Article 3 (commencing with Section 39660), the airborne toxic control measure applicable to the toxic air contaminant shall be adopted following the procedures and meeting the requirements of Article 4 (commencing with Section 39665). (b)  If a substance is designated as a toxic air contaminant because it is listed as a hazardous air pollutant pursuant to subsection (b) of Section 112 of the federal act (42 U.S.C. Sec. 7412(b)), the state board shall establish the airborne toxic control measure applicable to the substance as follows: (1)  If an emission standard applicable to the hazardous air pollutant has been adopted by the Environmental Protection Agency pursuant to Section 112 of the federal act (42 U.S.C. Sec. 7412), except as provided in paragraphs (2), (3), and (4), that emission standard adopted pursuant to Section 112 of the federal act (42 U.S.C. Sec. 7412) for the hazardous air pollutant is also the airborne toxic control measure for the toxic air contaminant. The state board shall implement the relevant emission standard and it shall be the airborne toxic control measure for purposes of this chapter. The implementation of the emission standard is not subject to Chapter 3.5 (commencing with Section 11340) of Part 1 of Division 3 of Title 2 of the Government Code or Article 4 (commencing with Section 39665). (2)  If an emission standard applicable to the hazardous air pollutant has been adopted by the Environmental Protection Agency pursuant to Section 112 of the federal act (42 U.S.C. Sec. 7412) and the state board finds that the emission standard does not achieve the purposes set forth in subdivision (b) or (c), as applicable, of Section 39666, the state board shall adopt an airborne toxic control measure for the toxic air contaminant that it finds will achieve those purposes. The state board shall, when it adopts an airborne toxic control measure pursuant to this paragraph, follow the procedures and meet the requirements of Article 4 (commencing with Section 39665). (3)  If the state board implements an airborne toxic control measure applicable to the substance pursuant to paragraph (1) and later finds that the purposes set forth in subdivision (b) or (c), as applicable, of Section 39666 are not achieved by the airborne toxic control measure, the state board may revise the airborne toxic control measure to achieve those purposes. The state board shall, when it revises an airborne toxic control measure pursuant to this paragraph, follow the procedures and meet the requirements of Article 4 (commencing with Section 39665). The state board may revise an airborne toxic control measure pursuant to this paragraph only if it first finds that the reduction in risk to the public health that will be achieved by the revision justifies the burden that will be imposed on persons who are in compliance with the airborne toxic control measure previously implemented pursuant to paragraph (1). (4)  If an emission standard applicable to the hazardous air pollutant has not been adopted by the Environmental Protection Agency pursuant to Section 112 of the federal act (42 U.S.C. Sec. 7412), the state board may adopt an airborne toxic control measure applicable to the toxic air contaminant pursuant to Article 4 (commencing with Section 39665). (Added by Stats. 1992, Ch. 1161, Sec. 3. Effective January 1, 1993.)