Smoke Alarm Guidelines

Toxic smoke and fumes kill. In a house fire, it is the flames that do the structural damage, but smoke is the primary danger to people. The majority of deaths in fires come from smoke poisoning.

Modern homes contain many materials, such as wood, wool, nylon and plastics, which when burning, produce heavy smoke and toxic fumes such as carbon monoxide and cyanide gas. These materials can smoulder for extended periods of time, producing substantial smoke and fumes before they burst into visible flames.

If you are asleep when a fire starts, you could suffer from smoke inhalation before you wake up. In fact, the combination of toxic smoke and gases and reduced levels of oxygen in the air can make waking up extremely difficult and in some circumstances, tragically impossible. So, it is essential to install and maintain working smoke alarms that will detect the smoke and sound an alarm.

Recent research indicates that house fires today burn faster and kill quicker than house fires 30 years ago. Research in the 1970s showed a safe escape time of 17 minutes. In 2005, this has decreased to an escape time of 3 minutes, or less in some circumstances. This drastic drop in escape time is primarily due to the contents of our modern homes, such as furnishings, that burn faster and more intently. This reduced escape time highlights the need for home fire escape planning and performing periodic practice drills.

• Over 90% of residential fires in Ontario are preventable.
• An injury is reported in 1 out of every 17 preventable home fires, and not all injuries are reported.
• 1 out of every 100 preventable residential fires is a fatal fire.

Research from 1995 to 2004 regarding preventable, fatal residential fires in Ontario indicates:

• 35% of fires – a smoke alarm was present and operated.
• 25% of fires – a smoke alarm was present and did not operate.
• 21% of fires – no smoke alarm was present.
• 19% of fires – smoke alarm operation was undetermined.

This research pertains to 609 fatal fires that occurred in Ontario from 1995 to 2004. In about 50 per cent of fatal home fires, there was no smoke alarm warning. In the majority of these fatal home fires, it was determined a dead battery or no battery installed was the reason for the smoke alarm failing to activate.

Statistics also indicate the holiday season between November and the end of January to be the highest point of the year for fires and related fatalities. From November 1, 2004 to January 31, 2005, alone there were 35 fire fatalities in Ontario. This highlights the need to exercise extra caution during the holiday season when we may be most distracted.

(Statistical Source: Office of the Ontario Fire Marshal)

Often you hear people using the terms smoke alarms and smoke detectors interchangeably. However, there is a difference between the two. What’s the difference?

A smoke alarm is an all-in-one, self-contained device, with a detector, which senses the products of combustion (smoke) and sounds an audible, and sometimes visual warning or alarm. Smoke alarms are widely used in residential settings. Put simply, a smoke alarm detects smoke and sounds an alarm.

A smoke detector is strictly a sensing device only, which senses the products of combustion (smoke) and sends a signal to a building’s fire alarm system to activate an audible, and sometimes visual warning or alarm. Smoke detectors must be connected to a building’s fire alarm system and are NOT a stand-alone unit. Put simply, a smoke detector senses smoke only and must be connected to a fire alarm system control panel. Smoke detectors are a detection device only – not an alarm.

Ionization smoke alarms use a small amount of radioactive material that ionizes the air between two electrically charged plates, causing a current to flow between the plates. When smoke enters the chamber, it changes the flow of current, which is detected and activates the alarm.

Ionization smoke alarms activate more quickly for fast, flaming fires with little visible smoke.

Advantages

• Cheaper than other types of smoke alarms
• Very good with fast flaming fires with little visible smoke
• Suitable for general use
• Less prone to false alarms due to dust and steam

Disadvantages:

• Very susceptible to nuisance alarms due to cooking
• May be slow to respond to slow smouldering fires
• Contain radioactive material

A photoelectric (optical) smoke alarm “sees” the smoke. NOTE: The term photoelectric does not refer to the power source for the smoke alarm. The power supply can be battery or direct-wired on the household electrical current (110v A/C). Both types are available to the consumer. Photoelectric (optical) smoke alarms operate on the principle of light scattered from the surface of particles. Smoke entering the sensing chamber reflects light onto the sensor, which triggers the alarm. Because large particles have much more surface area than small particles, a photoelectric smoke alarm is more sensitive to the large smoke particles produced in a smouldering fire.Photoelectric (optical) smoke alarms are particularly more responsive to smouldering fires and the dense smoke given off by foam-filled furnishings.

Advantages:

• Good for smouldering fires and dense smoke
• Not as prone to cooking nuisance alarms
• Contain no radioactive material
• Suitable for general use

Disadvantages:

• Prone to nuisance alarms from dust and insects – must be kept clean
• More expensive

In the normal case, the light from the light source shoots straight across and misses the sensor. When smoke enters the chamber, however, the smoke particles scatter the light and some amount of light hits the sensor, activating the alarm.

Combination Ionization / Photoelectric (Optical) alarms combine the two technologies, ionization and photoelectric, to detect the presence of smoke or products of combustion. An alarm can be activated by either of the sensors within the unit. A combination Ionization / Photoelectric (Optical) alarm gives you the benefits of both types of technologies.

Smoke alarms that combine carbon monoxide detection and smoke detection capabilities are also available in a single unit. These units incorporate different sounding alarms, or in some cases voice alerting of “Fire / Fire” or “Warning Carbon Monoxide” when detecting the presence of smoke and/or carbon monoxide. If a combination smoke alarm / carbon monoxide alarm is used, it must be installed on the ceiling to ensure that it will detect smoke effectively. Follow the manufacturers instructions.

A 9v alkaline battery powers most battery-operated smoke alarms. Some manufacturers also offer battery-operated smoke alarms powered by a long-life lithium battery.

The Ontario Building Code has required direct-wired smoke alarms be installed in all new home construction since 1986, with amendments and additional requirements over the years.

When smoke alarms are being replaced, the replacement unit must not reduce the level of detection required by the Building Code in effect at the time of construction of the residence, or by municipal by-laws in effect before the Fire Code adopted this requirement. This requirement is contained in Sentence 6.3.3.5.(1)of the Fire Code. In other words, existing direct-wired or hard-wired smoke alarms or electrically interconnected smoke alarm installations must be maintained to provide the same level of protection as originally required. Any replacement smoke alarms must be of a type comparable to the original or better. Any smoke alarms installed in addition to the requirements of Section 2.13 of the Fire Code are permitted to be battery powered.

Direct-wired smoke alarms can be “interconnected” or linked to one another, which means that should one smoke alarm activate in the home it will automatically sound the alarm on all smoke alarms within the home that are connected. People who sleep with their bedroom doors closed or may have difficulty awakening to a smoke alarm sounding outside the sleeping area should strongly consider installing interconnected direct-wired smoke alarms in their home.

Remember, smoke alarms connected directly to your home’s electrical power supply (A/C) will not work during hydro outages unless they have a battery back up feature. Some older models of these alarms do not have an internal battery backup. Find out what type of alarms you have in your home and ensure you are protected by battery operated smoke alarms in the event of a power failure in your home.

Both the Ontario Building Code and Ontario Fire Code require the installation of smoke alarms in residential occupancies. By definition, a smoke alarm must sound an audible alarm to alert the home’s occupants. Unfortunately, an audible alarm may not alert an individual who is deaf, deafened or hard of hearing.

There are numerous smoke alarms available on the market today that address the specialized needs of these individuals. Some devices utilize a bright flashing strobe light, as well as an audible alarm, to alert the residents in the event of a fire. Due to the electrical supply requirements to operate these strobe lights, they must be wired directly into the home’s 110v A/C electrical system. Some models have a 9v battery backup that will ensure the audible alarm will activate in the event of a power failure, however the battery will not activate the strobe light.

Additional options also exist that allow the individual to connect their smoke alarms to an alerting system that may incorporate a flashing strobe light, vibrating pager and/or vibrating bed shaker to alert the resident to the emergency. Other suitable options are also available.

A catalogue detailing all available options for the deaf, deafened or hard of hearing is available through The Canadian Hearing Society. You can contact The Canadian Hearing Society by calling 519-253-7241 (TTY: 519-254-1704). Their Head Office contact numbers are 1-800-465-4327 (TTY: 1-800-537-6030) and their website is www.chs.ca.

Cooking vapours and steam can sometimes activate a smoke alarm when no fire emergency is present. These are considered nuisance alarms and are the primary reason for people illegally disabling their smoke alarms by removing batteries or disconnecting the power supply to their smoke alarms. This practice of disabling a smoke alarm is extremely dangerous and against the law!

Smoke alarm manufacturers offer smoke alarms with a “HUSH” or “PAUSE” feature that allows the resident to temporarily silence the nuisance alarm. Generally, the HUSH feature will silence the alarm for approximately 7 minutes and then automatically reset itself. The smoke alarm will indicate that it is in HUSH mode by use of a periodic “chirp” or a visual indicator, such as a flashing LED light.

NOTE: Dense smoke will override the “HUSH” control feature and sound a continuous alarm to alert you to a fire emergency.

CAUTION: Before using the “HUSH” feature, identify the source of the smoke and be certain a safe condition exists.

Homeowners are responsible for installing and maintaining smoke alarms.

Landlords are responsible for ensuring their rental properties comply with the law. They must also provide tenants with a copy of the smoke alarm manufacturer’s maintenance instructions.

Tenants of rental properties should contact their landlord immediately if their occupancy does not have the required number of smoke alarms, or if there are any problems or concerns with the alarms.

Ensure that your children recognize the sound of your home’s smoke alarms and know what to do when they hear that sound. Develop and practise a home fire escape plan with your family.

Research has shown that children tend to sleep much more deeply and longer than adults. The sound of a smoke alarm may not penetrate the deep sleep patterns of children. As children can be “deep sleepers”, caregivers should never assume that activated smoke alarms would awaken and alert their sleeping children. As part of their home fire escape plan, caregivers must make it their responsibility to awaken and evacuate children in the event of a fire.You may have recently seen news reports on television showing children sleeping through the sound of smoke alarms, but awakening rather quickly to the sound of a familiar, abrupt voice coming from a smoke alarm with voice recording capabilities. Although smoke alarms with voice recording capabilities may seem like a good idea, the Ontario Fire Marshal’s Office is not aware of any voice recording smoke alarms that have met the Canadian standard for smoke alarms, CAN/ULC-S-531, Standard for Smoke Alarms, or that they will consistently awaken sleeping children. We understand that Underwriters Laboratories (UL) is currently reviewing this product, and that Underwriters Laboratories of Canada (ULC) approval will be sought in the future.

Anyone who purchases one of these alarms should use discretion when recording a message. It is important that the message be applicable to any and all fire situation.

Residential ionization smoke alarms contain an extremely small amount of radioactive material, americium 241 (33 kilobecquerel – kBq). This is comparable to the background radiation already present in many materials.

The Canadian Nuclear Safety Commission has confirmed that individual smoke alarms containing americium 241 may be disposed of in the regular garbage. However, if the smoke alarm contains radium or if there are large numbers of smoke alarms to be disposed of, more than 10 units, they should be shipped to the Low Level Radioactive Waste Management Office for disposal. Their contact number is 613-998-6748.