How to Dispose of Smoke Detectors

Two Types — and It Matters

There are two kinds. Ionization detectors contain a tiny sealed source of radioactive Americium-241 (look for an 'I' or the word 'ionization,' or a radiation symbol, on the back). Photoelectric detectors use a light sensor and contain no radioactive material. The type determines disposal: photoelectric and carbon-monoxide detectors are handled as electronics/e-waste or per local trash rules, while ionization units are best routed to a manufacturer take-back or a household hazardous waste (HHW) program.

Are They Dangerous? (No, If Intact)

Barely radioactive and safe to handle. Most ionization detectors contain one microcurie or less of Am-241, sealed inside a foil-and-ceramic chamber. The EPA states there's no health threat as long as the detector isn't damaged and is used as directed, and the NRC calculates a household with two detectors receives less than 0.002 millirem per year — far below natural background radiation. The key rule: never take the unit apart, crush it, or burn it, and never try to remove the americium source.

Best Route: Manufacturer Mail-Back

Both major makers run free consumer mail-back programs for ionization detectors (you pay only postage). First Alert accepts units branded First Alert, BRK, FamilyGard or Onelink — up to four at a time (call 1-800-323-9005 or see support.firstalert.com). Kidde accepts Kidde, Firex, Fyrnetics or Edwards units (including combination CO units): call 1-800-880-6788 first for a Return Authorization Number and the ship-to address. Remove the battery and ship by ground (not air). The NRC says household ionization detectors can also go in regular trash in most areas — but mail-back is preferred, and you must NOT trash them if your community incinerates its waste (they can trip radiation alarms).

Retailers, Battery & Combo Units

Don't count on stores: Home Depot, Lowe's and Best Buy generally don't take old smoke detectors, so use manufacturer mail-back or your local HHW facility. Always remove the battery first — for a 9-volt, tape the terminals (they can short and start a fire) and recycle it at a battery drop-off. For combination smoke + carbon-monoxide detectors, the CO part has no radioactive source; if the unit is also ionization, dispose of the whole thing through the ionization route after removing the battery.

Frequently Asked Questions

What's the best way to dispose of old smoke detectors?

Identify the type first (ionization vs photoelectric). For ionization units the greenest route is the manufacturer's free mail-back program (First Alert or Kidde); they can also go in regular trash in most areas per the NRC, but not if your community incinerates waste. Photoelectric and CO units go to e-waste or per local rules. Your HHW facility takes them too. Remove the battery first.

Are smoke detectors radioactive and dangerous?

Only ionization detectors, and only slightly — about one microcurie of Americium-241 sealed in foil and ceramic. The EPA says there's no health threat when the unit is intact and used as directed (under 0.002 millirem/year for a two-detector home). Never disassemble, crush or burn one. Photoelectric detectors contain no radioactive material.

How does manufacturer mail-back work?

First Alert takes back First Alert/BRK/FamilyGard/Onelink units (up to 4; you pay postage) — call 1-800-323-9005. Kidde takes Kidde/Firex/Fyrnetics/Edwards units: call 1-800-880-6788 first for a Return Authorization Number and address. Remove the battery and ship by ground. It's the responsible route because the maker properly handles the radioactive source.

Do Home Depot or Best Buy recycle smoke detectors?

Generally no — big-box retailers don't have a standard take-back for smoke detectors. Use the manufacturer mail-back programs or your local household hazardous waste facility. And always pull the battery first; tape a 9-volt's terminals and recycle it — see our battery recycling guide.