There is a New California State Law regarding Carbon Monoxide Detectors.
First of all, what is Carbon Monoxide? Carbon Monoxide is also called Carbon Oxide (CO). It is a colorless, odorless, and tasteless gas which is slightly lighter than air. It is highly toxic to humans and animals in higher quantities. Carbon Monoxide is produced whenever any fuel, such as gas, oil, kerosene, wood, or charcoal, is burned. Symptoms of carbon monoxide poisoning are often mistakenly diagnosed as the flu.
The new Carbon Monoxide Poisoning Prevention Act (Senate Bill 183) requires owners of all existing single family homes with an attached garage or a fossil fuel source, to install a CO alarm device by July 1, 2011. Owners of multi-family leased or rental homes, such as apartment buildings have until January 1, 2013 to comply with the law.