Carbon monoxide detectors are required under Amanda's Law which took effect in January of 2009. The law requires a minimum of 1 carbon monoxide (CO) detector in every home that has a source of carbon monoxide. An example of sources of CO is car exhaust, gas or oil heat, gas or oil hot water and a working fireplace. The placement of this detector shall be in the lowest story having a sleeping area. It is highly recommended that one detector be placed on each level of the home.