Existing law generally designates the State Air Resources Board as the state agency with the primary responsibility for the control of vehicular air pollution, and designates air pollution control districts and air quality management districts with the primary responsibility for the control of air pollution from all sources other than vehicular sources. Existing law requires the state board to inventory sources of air pollution within the air basins of the state, determine the kinds and quantity of air pollutants, and monitor air pollutants in cooperation with districts and other agencies. Existing law requires the state board to adopt standards of ambient air quality for each air basin in consideration of the public health, safety, and welfare, including, but not limited to, health, illness, irritation to the senses, aesthetic value, interference with visibility, and effects on the economy. Existing law authorizes these standards to vary from one air basin to another. Existing law requires the standards relating to health effects to be based upon the recommendations of the Office of Environmental Health Hazard Assessment. This bill would require, on or before January 1, 2030, the office to develop health-based threshold levels for hydrogen sulfide. The bill would further authorize the office to develop threshold levels for additional air pollutants with the considerations specified for hydrogen sulfide upon an appropriation for this purpose from the Legislature. The bill would require the office to conduct at least 3 public workshops, including at least one located in the Tijuana River Valley region, at least one located in the Salton Sea region, and at least one selected in consultation with a community that has experienced significant hydrogen sulfide exposure. The bill would require the air pollution control districts and air quality management districts to adopt, and would authorize local environmental and public health agencies to consider, any threshold level later developed by the office pursuant to the bill. By imposing new duties on air pollution control districts and air quality management districts, the bill would impose a state-mandated local program. The bill would also authorize the state board to adopt additional or updated standards based on the threshold levels developed pursuant to the bill. The bill would additionally express the intent of the Legislature to develop guidelines that would require the state board, in consultation with specified entities, to develop a response framework to establish best practices and guidance based on the office's development of thresholds established pursuant to the bill. The California Constitution requires the state to reimburse local agencies and school districts for certain costs mandated by the state. Statutory provisions establish procedures for making that reimbursement. This bill would provide that no reimbursement is required by this act for a specified reason.