ISO 7240-8:2007 specifies requirements, test methods and performance criteria for point multi-sensor fire detectors that incorporate an electrochemical cell for sensing carbon monoxide (CO) in combination with one or more heat sensors, for use in fire detection and alarm systems installed in buildings. For the testing of other types of CO multi-sensor fire detectors, or CO and heat multi-sensor fire detectors working on different principles, ISO 7240-8:2007 can be used for guidance. CO and heat multi-sensor fire detectors with special characteristics and developed for specific risks are not covered by ISO 7240-8:2007.