Smoke Detectors

It sounds when electrically charged (“ionized”) particles released in a fire interfere with the electrical current that flows through the alarm’s detection chamber. The disruption in the current causes the smoke alarm to sound.

It sounds when smoke particles interfere with and reflect the alarm’s light beam that travels through the alarm’s detection chamber, thereby triggering the alarm.

Some studies have shown that ionization smoke alarms may be more prone to nuisance alarms, such as those that occur due to cooking. Consumers may reduce that potential by placing ionization smoke alarms at least 20 feet from appliances, or by installing a photoelectric alarm near a cooking area. Most smoking-material fires, which tend to smolder, begin in a den, family room, living room or a bedroom. Families with members who smoke may consider installing photoelectric alarms or dual sensor alarms in those areas.