Where should CO detectors be placed in a fire alarm system?

• A. It detects carbon monoxide as a hazard; used in locations where CO hazards exist such as parking garages or utility rooms.
• B. It detects CO hazards only in living spaces.
• C. It is used outdoors only.
• D. It is used to detect smoke.

Answer: (A)

CO detectors are designed to sense carbon monoxide, a dangerous, odorless gas produced by incomplete combustion. Because of that, they belong in places where CO hazards exist, such as parking garages or utility/mechanical rooms where vehicles, furnaces, boilers, or other fuel-burning equipment are present. They are not meant to detect smoke or to be placed outdoors, where readings can be unreliable due to weather and air currents. Installing them in indoor areas with potential CO sources gives the earliest warning and helps keep occupants safe.