What is the difference between photoelectric and ionization smoke alarms?
There are generally two types of smoke alarms – ionization smoke alarms and photoelectric smoke alarms. All fires produce smoke particles in varying number and size.
Ionization smoke alarms are generally more sensitive than photoelectric smoke alarms at sensing small smoke particles.
Sources of small smoke particles:
- Hot, flaming fires that consume combustible materials rapidly and may spread quickly, such as:
- Fires from a burning paper in a wastebasket
- Kitchen grease fires
Photoelectric smoke alarms are generally more sensitive than ionization smoke detectors at sensing large smoke particles
Sources of large smoke particles:
- Slow, smoldering fires that may burn slowly, such as:
- Fires from burning upholstery
- Fires from burning bedding
For maximum protection, use both types of technology, such as in the Dual Sensor Smoke Alarm, on each level and in every bedroom of your home. Read more about choosing the right alarm, where to place home safety products and other fire safety information in our guide, Where to install smoke and carbon monoxide alarms.
How can I tell if my alarm is ionization or photoelectric?
First Alert Alarms come in ionization, photoelectric, and dual-sensor varieties. The alarm sensor technology is noted on the back of the alarm and on its packaging:
