What should I do if the alarm sounds and I smell a strong chemical odor?

If the alarm triggers and you detect a strong smell of gas or chemicals (carbon monoxide is colorless and odorless), it may be a false alarm caused by chemical gases damaging the sensor. Remove the alarm and place it in fresh air with power off for at least 30 minutes to 1 week maximum. If it doesn't recover after one week in fresh air (LCD shows 0 PPM), the sensor is damaged and the alarm should be removed from service.