A carbon monoxide (CO) detector is a life-saving device designed to monitor the presence of carbon monoxide in the air. Carbon monoxide is often called the "silent killer" because it is odorless, colorless, and highly toxic. It is produced when carbon-based fuels—such as gasoline, oil, or natural gas—burn incompletely. Common sources include running vehicles, furnaces, water heaters, stoves, and generators.
CO detectors measure carbon monoxide levels in parts per million (ppm) over time. If the CO concentration reaches dangerous levels, the detector sounds an alarm to warn occupants. The higher the CO level, the faster the alarm will activate to prevent poisoning.
In commercial buildings, CO detectors are typically required in areas where CO-producing equipment is present, such as hotel rooms, schools, mechanical rooms, and indoor garages. Local building codes determine specific installation requirements.
CO detectors do not produce the same alarm noise as smoke and heat detectors. Instead, they have a built-in "temporal four" tone—a unique alarm pattern with four on-and-off sequences followed by a five-second pause. This distinct sound helps occupants differentiate a CO alarm from a fire alarm, prompting them to take appropriate action, such as opening windows, shutting off potential CO sources, and evacuating the area.
CO detectors are a critical safety feature in both residential and commercial environments, helping prevent carbon monoxide poisoning by providing early detection and warning before dangerous exposure occurs.
