Smoke Alarms

Most fatal fires occur at night when people are asleep. Often, victims never wake up. A working smoke alarm will detect smoke and sound an alarm to alert you, giving you precious time to escape. The Ontario Fire Code requires that every home have working smoke alarms.

Frequently Asked Questions

What is a smoke alarm?

A smoke alarm is a battery operated or electrically connected device that senses the presence of visible or invisible particles produced by combustion. It is designed to sound an alarm within the room or suite within which it is located.

Are smoke alarms effective?

According to studies published by the National Fire Protection Association, having a smoke alarm cuts your risk of dying in a fire by nearly half. However, a smoke alarm should be part of an overall home fire safety strategy that also includes preventing fires by adopting fire safe behaviour, and developing and practicing a home fire escape plan. In a fire, escape time may be very limited. Therefore, escape plans are a critical aspect of a home fire safety strategy.

What's the best alarm?

There are many types of smoke alarms, each with different features. Alarms can be electrically connected, battery powered or a combination of both. This combination - and a pause feature to reduce nuisance alarms - are highly recommended.

There are two types of household smoke alarms in common use. These are known as ionization or photoelectric type smoke alarms.

Ionization Alarms

Ionization alarms use a small amount of radioactive material to ionize air in the sensing chamber. As a result, the air chamber becomes conductive permitting current to flow between two charged electrodes. When smoke particles enter the chamber, the conductivity of the chamber air decreases. When this reduction in conductivity is reduced to a predetermined level, the alarm is set off. Most smoke alarms in use are of this type. Advantages to ionization alarms include:

Fastest type to respond to flaming fires
Lowest cost and most commonly sold
Some models have a hush or temporary silence feature that allows silencing without removing the battery
Some models are available with a long life battery

Photoelectric Alarms

A photoelectric smoke alarm consists of a light emitting diode and a light sensitive sensor in the sensing chamber. The presence of suspended smoke particles in the chamber scatters the light beam. This scattered light is detected and sets off the alarm. Advantages to photoelectric smoke alarms include:

Fastest type to respond to slow smoldering fires and white or grey smoke
Less prone to nuisance alarms from cooking

What features can I expect on a current model?

These are some features you can expect to find:

a "missing battery" indicator
an optional alarm hush or silence feature
the use of a power "on" indicator light to show that ac power is being supplied to 120 volt wired in smoke alarms

What are "long life" smoke alarms?

Long life smoke alarms have been designed to use lithium batteries where the battery life is predicted to last 10 years with the normal low battery drain of ionization type smoke alarms. The smoke alarms are still designed to provide a low battery audible signal as the battery charge is reduced to a level that may make the smoke alarm inoperable. It should be noted that although these batteries are designed to last 10 years, ongoing testing and maintenance is required as per manufacturers' instructions.

Can long life lithium batteries be used in any smoke alarm?

No. Only battery types recommended by the manufacturer should be used in a smoke alarm. Incorrect batteries may not provide the operating characteristics expected of the smoke alarm.

How do I know my smoke alarms will work?

We have every reason to believe that alarms listed by a certification agency accredited by the Standards Council of Canada will function as intended.

To ensure that an alarm has been manufactured and tested to an acceptable standard, there should be a marking by the Underwriters Laboratories of Canada (ULC), or Underwriters Laboratories Incorporated (cUL).

How many smoke alarms do I need?

One smoke alarm is not enough! Install smoke alarms on every level of your home and near sleeping areas. If you or your loved ones sleep with bedroom doors closed, install an alarm inside each bedroom.

Where should I install smoke alarms?

Because smoke rises, you should place alarms on the ceiling. If you cannot do this, place them high up on a wall, according to manufacturer's instructions. There are certain locations to avoid such as near bathrooms, heating appliances, windows, or close to ceiling fans.

How often should I test my smoke alarms?

Every month, test your smoke alarms, using the alarm test button. Once a month test your alarms using smoke from a smoldering cotton string. Follow your owner's manual.

I can't reach my smoke alarm. How do I test it?

If you have difficulty reaching your alarms, use a broom handle or a cane to gently press the test button for 30 seconds. If the alarm doesn't sound, replace the battery or the alarm immediately.

When should I change my smoke alarm batteries?

Install a new battery of the proper type at least once a year. If the low battery warning beeps, replace the battery immediately. We change our clocks each spring and fall so this is a good time to change your smoke alarm batteries too.

How else should I maintain my smoke alarm?

Gently vacuum alarm every six months. Dust can clog a smoke alarm, so carefully vacuum the inside of a battery powered unit using the soft bristle brush. If electrically connected, shut off the power and vacuum the outside vents only. Restore power and test unit when finished.

When should I replace my smoke alarm?

Smoke alarms do wear out, so if you think your alarms are more than 10 years old, replace them with new ones. Why not replace them with long-life smoke alarms that will eliminate the need for annual battery replacement and the potential hazard of dead batteries for up to 10 years.

What is a good fire escape plan?

Make sure that everyone knows the sound of the smoke alarm and what to do if a fire occurs. Regularly practice your home fire escape plan. Know two ways out of every room and have a pre-arranged meeting place outside. Once out, stay out and call the fire department from a neighbour's home.