The New York City mayor, Michael R. Bloomberg, signed legislation, which requires all new carbon monoxide alarms to have audible and visual end-of life signals. In August of 2009, the Underwriters Laboratory standard UL2034 required all CO alarms made after August of that year to have some sort of visual and audible signals. Typical those signals can be LED and beeper. An end-of-life signal is dictated by the UL standard as 2 beeps and 2 flashes every thirty seconds. This is a very good idea and should be extended to UL2075 for system CO and smoke detectors.
At a Public Hearing in December 2011 on Local Laws Mayor Bloomberg stated "The first of eight bills before me today is Introductory Number 746, sponsored in conjunction with the Administration by Council Members Dilan, Weprin, Jackson, Mark-Viverito, Lander, Barron, Chin, Crowley, Eugene, Ferreras, Gennaro, Greenfield, Mealy, Palma, Recchia, Rose, Van Bramer, Williams and Halloran. Introductory Number 746 requires all newly installed carbon monoxide alarms to have an audible signal that alerts residents when they expire and requires the replacement of carbon monoxide alarms upon their expiration.”
Carbon monoxide is an odorless and poisonous gas produced by combustion of fossil-fuels, including, gasoline engines, gas lights, BBQ, wood, natural gas, propane and fuel oil. Some of these fossil fuels are used in furnaces, water heaters, boilers, and other appliances.