ISO 7240-6:2004 specifies requirements, test methods and performance criteria for point fire detectors using electro-chemical cells that operate using carbon monoxide detection principles for use in fire detection and fire alarm systems installed in buildings (see ISO 7240-1). CO fire detectors conforming to ISO 7240-6:2004 might not be suitable for other uses. For the testing of other types of fire detectors, or smoke detectors working on different principles, ISO 7240-6:2004 should be used only for guidance. Fire detectors with special characteristics and developed for specific risks are not covered by ISO 7240-6:2004.