The average smoke detector’s lifespan is 10 years, but when that time is up, what’s the best way to dispose of it? While it is legal to dispose of smoke detectors in a landfill—they are not classified hazardous waste—a better option is to recycle them.
What detector type do you have?
There are four types of smoke detectors available for consumer purchase:
- Ionization – The most common type of smoke detector, ionization smoke detectors are quicker at sensing flaming, fast moving fires. This type of detector uses a small amount of radioactive material to ionize air in an internal sensing chamber. When smoke particles enter the chamber, the conductivity of the chamber air will decrease. When this reduction in conductivity is reduced to a predetermined level, the alarm is set off.
- Photoelectric – Photoelectric smoke detectors are quicker than ionizing detectors at sensing smoldering fires. A photoelectric detector consists of a light emitting diode and a light sensitive sensor located in a sensing chamber. The presence of suspended smoke particles in the chamber scatters the light beam. This scattered light is detected by the light sensitive sensor which sets off the alarm.
- Dual-sensor – Dual-sensor smoke detectors combine ionization and photoelectric technology in one detector.
- Combination smoke/CO – These types of detectors can detect both smoke and carbon monoxide. Depending on the type of smoke detector in this combination, they may or may not contain radioactive material.
You can look at the back of your smoke detector to determine which type you have.
The National Fire Protection Association (NFPA) recommends that consumers purchase both photoelectric and ionization smoke detectors or a dual-sensor alarm.
How often should I replace my detector?
The NFPA recommends consumers replace smoke detectors when they are 10 years old or sooner if they do not respond properly when tested. The NFPA also recommends you replace smoke alarms when you move into a new home if you do not know their age. Check the expiration date on your smoke detector the next time you replace the batteries.
Why not just throw it in the trash?
Most in-home smoke detectors are the ionizing type. When thrown in the trash, the radioactive component can be damaged during collection and processing leading to radioactive exposure. Both ionizing and photoelectric detectors have printed circuit boards which contain heavy metals such as lead, cadmium and mercury.
Both Midwest Recycling Center (drop off, fees apply) and Curie Environmental Services (mail back) accept all brands of smoke detectors for recycling. Some brands offer mail-back recycling services for their brands only. If there’s no return information on your detector, contact the manufacturer directly. Fees are usually charged for shipping and handling. You can find manufacturer contact information on the back of the detector.
How are they recycled?
Plastic and metal components are separated and recycled. The radioactive component is shipped for final disposal at a licensed radioactive waste facility.