Contra Costa County, CA Building Safety: Carbon Monoxide Detectors (2026)

The Carbon Monoxide Poisoning Prevention Act of 2010 (SB 183) is codified in California Health & Safety Code 13260-13263 and incorporated into the California Residential Code (R315). It requires carbon monoxide alarms to be installed in every dwelling unit intended for human occupancy that has a fossil-fuel burning heater or appliance, a fireplace, or an attached garage. Single-family homes were first required to comply by July 1, 2011; all other dwelling units (apartments, condos, hotels, motels) by January 1, 2013. CO alarms must be installed outside each separate sleeping area in the immediate vicinity of bedrooms and on every level of the home, including basements. Combination smoke/CO alarms are acceptable if they meet both UL 217 and UL 2034 standards and are California State Fire Marshal listed. New construction requires hardwired CO alarms with battery backup, interconnected with smoke alarms when feasible. Battery-only CO alarms installed in California should meet current standards; most models now have 10-year sealed batteries. Sellers must disclose CO alarm compliance at time of sale. Landlords are responsible for installation and maintenance in rental units. Failure to maintain CO alarms can be enforced by code enforcement and carries serious civil liability given the lethal nature of carbon monoxide poisoning.