what radioactive material is in smoke detectors

Most ionization smoke detectors use a tiny amount of americium-241 as the radioactive material. Some older models used radium-226 , and a few commercial or specialized units have used nickel-63.

Quick scoop

Americium-241 is the standard answer for most modern home ionization smoke alarms.

It helps ionize the air inside the detector so the device can sense smoke particles.

Safety

The radioactive source is sealed inside the detector and shielded, so it is not a health risk when the alarm is intact and used normally.

The main warning is: don’t tamper with or open it.

Older detectors

• Radium-226 : used in early smoke detectors.

• Americium-241 : used in most current ionization smoke detectors.

• Nickel-63 : used in some commercial detectors and some residential units.

If you want, I can also explain the difference between ionization and photoelectric smoke detectors.