NFPA 72, Table 7.2.2, states that "detectors shall be tested in place to ensure smoke entry into the sensing chamber and an alarm response." Smoke! in a can lets you meet this requirement without contaminating the detector, without affecting its sensitivity, and without increasing the risk of false alarms. Patented formula evaporates completely.
Smoke! in a can is UL listed for all brands and models of photoelectric or ionization type smoke detectors. Its safe, non toxic formula contains no CFCs. After verifying smoke entry into the detector, you can walk away assured the Smoke! in a can will evaporate completely.