Smoke and Carbon Monoxide Detectors
Some smoke detectors contain a radioactive isotope that can be hazardous to humans and the environment. The device’s label and user manual should indicate if this is the case, and offer contact information for the manufacturer so the user can send the smoke alarm back to be recycled after it is no longer wanted. If you cannot locate the manufacturer of your smoke detector or if your smoke detector does not contain a radioactive isotope, it can be disposed of in your regular garbage.
Any device that is strictly for detecting carbon monoxide contains no radioactive materials and can be disposed of in your regular garbage.