In case you haven’t heard, The Carbon Monoxide Poisoning Prevention Act of 2010 (Cal. Health & Safety Code §§ 13260 et seq.) is now law. As of July 1, 2011, California homes need to have a carbon monoxide detector installed. This is not a “point of sale” ordinance just for people selling their homes, but instead is for all houses, condominiums, townhouses etc. (whether occupied by owners or tenants). For apartment buildings the deadline is later, January 1, 2013.
These detectors look a lot like smoke detectors and can be run on either batteries or plugged into the wall, depending on which model you purchase. Experts suggest that you place the detector in the sleeping area of the home and on every floor of it (including basement, if your dwelling has one).
To learn more, I suggest doing research online, and be sure to include the Consumer Reports information on carbon monoxide detectors too. The Cal Fire news release regarding the requirement can be viewed online also.