A chlorine gas generating candle in a vented container which serves as a portable means to generate heated chlorine gas for killing insects, bacteria, viruses and other dangerous biological agents. The device has application in sanitizing dwellings, swimming pools and the like, and is effective in case of accidental release and/or biological attack. The chlorine gas generating candle disinfects an enclosed space with a quantity of heated chlorine gas. The chlorine gas generator is a self contained unit including an igniter which can be activated to initiate a self propagating burn of the entire candle and a resultant distribution of toxic chlorine gas. The use of one or a plurality of chlorine generators described in this application can provide any desired concentration of the killing gas. The chlorine gas generating candle can be safely and easily transported and does not require a source of power to operate.