Smoke detectors, also called smoke alarms, are essential in all homes and businesses. Over time, smoke detectors begin to lose their effectiveness and must be replaced with a new unit. The old one can then be recycled in several ways.
Remove the batteries.
Take off any extra plastic pieces from your smoke detector and recycle them with your regular plastics.
Mail your old smoke detector directly to the manufacturer--most will accept old units. The name of the manufacturer will be on the back of the unit.
Take your old smoke detector to a recycling center.