What is the primary function of smoke detectors?

The primary function of smoke detectors is to detect smoke, which is a key indicator of fire, and to alert occupants to the presence of that fire. Smoke detectors are designed to sense the particulate matter present in smoke, enabling them to provide an early warning to people in the vicinity. This early alert is crucial as it gives occupants time to evacuate the building and call for help, significantly increasing the chances of safety and reducing the risk of injury or loss of life.

Other options, while related to fire safety, do not align with the primary function of smoke detectors. Illumination during a fire is typically handled by emergency lighting systems rather than smoke detectors. Preventing fire from starting and extinguishing fires are functions typically associated with fire prevention measures and fire suppression systems, respectively, rather than the detection capabilities of smoke detectors.