There have been recent claims in the newspapers stating that smoke alarms utilizing ionization technology are less effective than photoelectric type smoke alarms. The claims state that there are significant delays in response times from ionization alarms and go on to suggest that people should replace their ionization smoke alarms with photoelectric or combination units.

The Office of the Fire Marshal (OFM) would like to stress that scientifically-based testing has been conducted by the Underwriters Laboratories of Canada (ULC) and Underwriters Laboratories Incorporated (UL) which have demonstrated that “both ionization and photoelectric smoke alarms…will respond as early warning devices well before a fire situation gets to be untenable and can provide sufficient time for escape. Quite simply, the science does not support claims that ionization smoke alarms are less effective than photoelectric alarms”.

Ionization and photoelectric alarms operate on different principles, and they may respond differently to various fire conditions. However, it is important to understand that regardless of the type of technology used – both alarms are tested to the same standard and must meet the same level of performance to achieve ULC listing. Since one cannot predict the type of fire that may occur, installing both types of alarms can enhance fire safety.

When purchasing smoke alarms, look for a product which bears the mark of an accredited certification organization. This signifies that the unit has been manufactured and tested to an acceptable Canadian standard. Two examples of such marks are as follows:

The OFM feels that a much more important issue than the type of smoke alarm technology people have is the number of people that die in fires in homes that are not equipped with any working smoke alarms. In Ontario, between 2005 and 2009, 63 fire fatalities occurred in preventable residential fires in homes where smoke alarms were either missing; had dead batteries or there were no batteries installed at all. Therefore, it is extremely important that working smoke alarms are installed and maintained.