How to Dispose of a Carbon Monoxide Detector

How to dispose of a carbon monoxide detector is simpler than disposing of some smoke alarms. Most standalone CO alarms use an electrochemical sensor and contain no radioactive material. The main things to handle are the battery and the electronics. Remove replaceable batteries for recycling, follow the instructions for sealed lithium units, and take the alarm itself to an electronics recycler or dispose of it according to local rules.

When to replace a CO alarm

CO sensors wear out. Many alarms are designed to last about 5 to 10 years, depending on the model, and many sound an end-of-life chirp or show a message when they expire. Look for a manufacture date or “replace by” date on the back. If the alarm is past that date, replace it even if it seems to work, because the sensor may no longer detect carbon monoxide reliably.

Check whether it is a combination unit

Combination smoke and CO alarms are different. If the unit includes an ionization smoke sensor, it contains a tiny amount of americium, a radioactive material. Those units are usually handled like ionization smoke alarms, often through a manufacturer mail-back program. The label usually says if a device contains radioactive material. See disposing of old smoke alarms for those.

Deal with the battery first

• Replaceable alkaline batteries: remove them. Many areas allow single-use alkaline batteries in the trash, while others collect them; check local rules.
• Replaceable lithium batteries: remove and tape the terminals, then take them to a battery drop-off.
• Sealed 10-year lithium batteries: many of these alarms have a switch or tab on the back to deactivate the battery permanently. Follow the maker’s instructions to disable it, which also silences the end-of-life chirp. Then recycle the unit as electronics, mentioning the built-in battery.
• Plug-in alarms with backup batteries: remove the backup battery and recycle it.

Where the alarm goes

1. Electronics recyclers and e-waste events often accept CO alarms.
2. Household hazardous waste programs may take them, especially units with sealed lithium batteries.
3. Manufacturer programs exist for some brands and models.
4. Trash, if your local program allows it, for standalone CO alarms with the battery removed. Some areas restrict electronics in trash, so check first.

Do not just take it down

Replace the alarm before removing the old one, or the same day. Carbon monoxide is colorless and odorless, and alarms are the only practical way to know it is present. Common guidance is to place CO alarms on every level of the home and outside sleeping areas, and near attached garages and fuel-burning appliances, following the maker’s placement instructions and local code.

How to dispose of a carbon monoxide detector FAQ

Are carbon monoxide detectors radioactive?

Standalone CO alarms typically are not. Combination units with an ionization smoke sensor contain a small amount of americium and need different handling.

How long do carbon monoxide detectors last?

Many are designed to last about 5 to 10 years. Check the date on the back or the maker’s instructions.

How do I stop an expired CO alarm from chirping?

Many sealed-battery models have a deactivation switch or tab. Follow the maker’s instructions, then replace the alarm.

Can I throw a CO detector in the trash?

In some areas, a standalone CO alarm with the battery removed can go in the trash. Many prefer it be recycled as electronics. Check local rules.

What do I do with the battery from a CO alarm?

Recycle lithium batteries at a battery drop-off with taped terminals. Check local rules for alkaline batteries.

The bottom line

How to dispose of a carbon monoxide detector starts with checking whether it is a combination smoke unit, which may need special handling. For a standalone CO alarm, remove or deactivate the battery as the maker instructs, recycle any lithium batteries, and take the alarm to an electronics recycler or follow local disposal rules. Install the replacement before the old one goes out the door.