San Francisco, CA Earthquake Safety: Seismic Gas Shutoff (2026)

Seismic (earthquake) gas shutoff valves are required in San Francisco under California Health and Safety Code Sections 19200-19204 and the California Referenced Standards Code (CRSC), Standard 12-12-1. Automatic earthquake shutoff valves must be installed on all new residential and commercial construction at the gas meter. For existing buildings, installation is required when the gas piping system is substantially altered, the building undergoes major renovation, or when required by local ordinance at the time of sale. The valves automatically shut off gas flow when shaking of sufficient magnitude occurs (typically calibrated to 5.1+ on the Richter scale). This prevents post-earthquake gas leaks that can cause fires and explosions, a major concern in San Francisco given the devastating fires following the 1906 earthquake. Installation must be performed by a licensed plumber or contractor and must comply with PG&E specifications. The valve must be installed on the building side of the gas meter, not the utility side. Excess flow valves, which shut off gas if a pipe is damaged, provide additional protection for underground service lines. The California Seismic Safety Commission has recommended expanded requirements, including mandatory installation on all older buildings.