These requirements cover electrically operated single and multiple station smoke alarms intended for open area protection in indoor locations, in accordance with Installation of Smoke Alarms, CAN/ULC-S553; National Building Code of Canada; and National Fire Code of Canada. This standard evaluates single station smoke alarms (e.g. ionization-type, photoelectric-type, smoke alarm with supplementary heat detection type, combination smoke type, multi-criteria type), as defined by these requirements, is a self-contained fire alarm device that consists of an assembly of electrical components including a smoke sensor / chamber, alarm sounding appliance, and provision for connection to a power supply source, either by splice leads, terminals, a cord and plug arrangement or containing integral batteries to detect one or more products of combustion. The products of combustion may consist of visible as well as invisible smoke particles, gases, heat, radiant energy, and water vapor. Additional functionality such as, a supplemental heat detector, terminals for connection to a remote audible signaling appliance (device) or accessory, and an integral transmitter to energize a remote audible signaling appliance (device) is permitted to be incorporated as part of the smoke alarm assembly. Smoke-alarms not intended for interconnection are defined as single-station type. Multiple station units are single station smoke alarms that are interconnected so that actuation of one results in alarm sounding by all interconnected smoke alarms , or smoke alarms that are connected to remote heat detectors or heat alarms (thermostats). These requirements, where applicable, also cover all remote accessories that are to be connected.This standard does not cover the following, smoke detectors of the non-self-contained type that are intended for connection to a household or industrial system control unit. These are included in CAN/ULC-S529, Smoke Detectors for Fire Alarm Systems; mechanically operated single and multiple station fire alarm devices that are specified in ULC-ORD-C539, Single and Multiple Station Heat Alarms; heat detectors [except for the requirements in the Fire Test smoke alarm with heat detection (Heat Detector), Section 65] incorporated as part of a single station smoke alarm assembly whose requirements are covered in the CAN/ULC-S530, Heat Actuated Fire Detectors for Fire Alarm Systems and/or when part of a multi-criteria smoke alarm; an accessory that is provided with a means to transmit alarm signals to a constantly attended, remote monitoring location. Any accessory capable of transmitting these types of signals is covered by the requirements in CAN/ULC-S545, Residential Fire Warning System Control Units; a gas and vapor detector or sensor incorporated as a part of a smoke alarm assembly, and covered by CSA 6.19-01 (R2006), Standard for Carbon Monoxide Alarming Devices, except when part of a multi-criteria smoke alarm.