Smoke Alarm and Carbon Monoxide Detector information provided by Kneehill Regional Fire Chief

Niall Sharpe is the Kneehill Regional Fire Chief and a Fire Safety Codes Officer for the province of Alberta. Niall noticed that the most common questions asked by the public during Fire Prevention Week, were about smoke alarms and carbon monoxide detectors; so he would like to provide some important information on these.
Smoke Alarms
The two basic types of smoke detectors or smoke alarms are ionization and photoelectric.
Ionization smoke detection is generally more responsive to fast flaming fires.
How they work: Ionization-type smoke alarms have a small amount of radioactive material between two electrically charged plates, which ionizes the air and causes current to flow between the plates. When smoke enters the chamber, it disrupts the flow of ions, thus reducing the flow of current and activating the alarm.
Photoelectric smoke detection is generally more responsive to slow fires that begin with a long period of smoldering (called "smoldering fires"). How they work: Photoelectric-type alarms aim a light source into a sensing chamber at an angle away from the sensor. Smoke enters the chamber, reflecting light onto the light sensor; triggering the alarm.
In Canada, all smoke alarms must be listed and meet the CAN/ULC-S531 standard. All smoke alarms perform acceptably for both slow and fast fires and provide early warning of fires at all times of the day or night, whether occupants are asleep or awake.
Evidence indicates that either type of smoke alarm will provide sufficient time for escape for most people for most fires. However, for the best protection, NFPA recommends both types of smoke alarms be installed in residential homes. In addition to individual ionization and photoelectric smoke alarms, there are combination alarms that include both technologies in a single smoke alarm. There are also wirelessly interconnected smoke alarms available now.
Installation & Maintenance
Smoke alarms become less effective with age and must be replaced every 10 years.
In Alberta, smoke alarms have been required in residential homes since 1984, these may be battery operated or can be hard-wired. These smoke alarms are required on every level of your home; including the basement (between the living areas and the sleeping areas). The National Fire Protection Association (NFPA) also recommends installing an alarm inside and outside every separate sleeping area. Since 2003, new homes are required to have smoke alarms on each floor level interconnected, so that when one alarm sounds, they all sound. This is an advantage in early warning, because it gives occupants extra time to escape if they are in one part of the home and a fire breaks out in another part.
In Alberta, smoke alarms have been required to be hard-wired since 1997; these operate on your household electrical current. They may also have battery backup power, in case of power failures. In addition to the residential smoke alarms that required by the Fire Code, you may install additional battery operated alarms.
If someone in your home is deaf or has hearing aids, consider installing a new smoke alarm that combines flashing lights or strobes with the audible alarm sound.
Always install smoke alarms high on ceilings or walls (as smoke will rise). Ceiling mounted alarms should be installed at least 4 to 6 inches away from the nearest wall; wall-mounted alarms should be installed 4 to 12 inches down from the ceiling.
If you have ceilings that are pitched (like cathedral ceilings), install the alarm near the ceiling's highest point, but about 4 to 6 inches below the peak, not at the peak.
Don't install smoke alarms near windows, doors, or air ducts where drafts or air currents might interfere with their operation and delay the alarm during a fire.
Never paint smoke alarms. Paint, stickers, or other decorations might stop the alarms from working properly.
You should dust or vacuum your smoke alarm regularly, with a soft brush attachment.
Almost two-thirds of all residential home fire deaths in North America, resulted from fires in homes with smoke alarms that had been disabled or not working and some with no smoke alarms installed. Always change your batteries every year and check your smoke alarms. Remember, change any smoke alarm that is older than 10 years.
Families & Smoke Alarm Testing: NFPA emphasizes the need to plan and practice a home fire escape and to make sure everyone in a home can be awakened by the sound of the smoke alarm. NFPA also suggests practicing the fire escape plan, during which the smoke alarm should also be activated, so all family members including children will recognize the alarm sound.
Every home fire escape plan is different, and every family should know who will – and who won't – awaken at the sound of the smoke alarm. If someone doesn't wake up when the alarm sounds during a drill. The family should design an escape plan that assigns a grown-up who is easily awakened by the alarm to wake the sleepers; they might try yelling "FIRE," banging on the wall or door, or blowing a whistle or air horn.
Nuisance Alarms
Steam from showers or cooking with the oven, stove or toaster, can cause smoke alarms to activate with a false alarm. If these types of nuisance alarms occur, never remove the battery or disable the smoke alarm. There are several options you can try to reduce nuisance alarms.
Relocate the alarm; sometimes moving the alarm can make the difference
Replace ionizing alarms located near kitchen areas with photoelectric types
Replace photoelectric alarms located near bathroom areas with ionizing types
Install a smoke alarm with a pause or hush button that will allow you to temporarily silence the alarm (some smoke alarms have a remote silence control)
Carbon Monoxide & CO Detectors
Prior to 2007, all residential mobile homes with a solid fuel burning appliance (wood stove), required CO detectors to be installed.
The current 2006 Alberta Building Code (effective September 2, 2007) requires CO detectors in all new houses if there is a fuel burning appliance; such as a furnace or water heater, or an attached garage. All CO Detectors in Canada must have a CSA approval.
CO detectors are also required in new condos/multi-family homes, if the unit has a self contained fuel-burning appliance or shares a wall or ceiling with a parking garage.
The presence of carbon monoxide, CO in our homes is extremely dangerous. Prevention is best, so always make sure that carbon monoxide never enters your home. To be safe, in case CO gets in; you should install at least one CO detector in your home or on every level.
What Is Carbon Monoxide? Carbon monoxide (CO) is an invisible, colourless and odourless poisonous gas. You can't see, taste or smell it, but it can quickly affect you or your family, before you even know it's there. Even at low levels of exposure, carbon monoxide can cause serious health problems and death. CO is harmful because it rapidly accumulates in the blood, depleting the ability of blood to carry oxygen. Early signs of CO poisoning are headaches, nausea and feeling drowsy or tired, as the CO affects the brain and the central nervous system
Why is Carbon Monoxide Dangerous? When carbon monoxide is inhaled into the body; it passes from the lungs into the hemoglobin molecules in the red blood cells. Carbon monoxide binds to hemoglobin at the same site as oxygen, forming carboxyhemoglobin. The hemoglobin prefers the carbon monoxide since it is easier to bind with than oxygen. Combines at a ratio of approximately 240 carbon monoxide molecules for every one oxygen molecule absorbed by your body, so even low levels can be deadly. Carboxyhemoglobin quickly interferes with the oxygen transport and gas exchange abilities of red blood cells. The result is that the body becomes oxygen-starved, which results in tissue damage and ultimately death.
Low levels of carbon monoxide poisoning cause symptoms similar to those of the flu or a cold; including shortness of breath on mild exertion, mild headaches, and nausea. Higher levels of poisoning lead to dizziness, mental confusion, severe headaches, nausea, vomiting, loss of coordination and fainting on mild exertion. Ultimately, carbon monoxide poisoning results in unconsciousness, permanent central nervous system damage and death.
Carbon monoxide detectors are set to sound an alarm before the exposure to carbon monoxide would present a hazard to a healthy adult. Young children, people with circulatory or respiratory ailments, pets and the elderly are more sensitive to carbon monoxide.
Features to consider when purchasing a CO detector: No detectors will operate properly forever. Replace CO detectors every five years. Look for a detector that is listed with the Canadian Standards Association (CSA) standard. The logos of the testing agency will be marked on the product.
There are plug-in CO detectors with battery backup power and battery operated CO detectors. There are also combination Smoke & CO detectors available as well.
Choose a detector with a memory if you want to monitor long-term, low-level exposure and short-term, high-level exposure. These units monitor and store low levels of CO, peak levels and concentrations; levels can be viewed later by pressing a recall button.
Battery operated units allow detector placement in most convenient locations. However, battery operated devices require diligence in replacing worn out batteries.
Do not connect plug in units to an electrical outlet that is controlled by a wall switch.
Where should you Install a CO Detector? Manufacturers generally provide the same installation instructions; the best place to put the CO detector is where you will hear it while sleeping. Carbon monoxide is roughly the same weight as air and will distribute evenly throughout a room or the house; so a detector can be placed at any height, in any location, as long as the detector's alarm can be heard.
To avoid both damage to the unit and to reduce false alarms, do not install CO detectors: in unheated basements, attics or garages; in areas of high humidity (near showers); in areas with exposure to chemical solvents or any cleaners, including hair spray, deodorant sprays, etc...; near any vents, flues or chimneys; within 6 feet (2 meters) of heating and cooking appliances (furnaces, stoves); near forced, or unforced-air ventilation openings (air drafts); within 6 feet (2 meters) of corners or areas where natural air circulation is low; where they may be damaged, such as an outlet in a high traffic area or outside.
Symptoms of Carbon Monoxide Poisoning are headaches, nausea, drowsiness, dizziness, confusion, loss of coordination or judgment.
If you, another person, or a pet show symptoms of CO poisoning: leave the house immediately; call 911 or the local emergency services from a neighbour's house; tell emergency responders that you suspect carbon monoxide poisoning; do not re-enter the house until emergency services confirm it is safe to do so; carbon monoxide is explosive when it reaches concentrations from 12% to 75% in air.
How Do Carbon Monoxide Detectors Work? Carbon monoxide detectors trigger an alarm based on an accumulation of carbon monoxide over time. As they age, the sensor becomes saturated over time, until they eventually become less effective. Carbon monoxide can harm you if you are exposed to high levels of carbon monoxide in a short period of time, or to lower levels of carbon monoxide over a long period of time. Carbon monoxide detectors require a continuous power supply, so if the power cuts off then the alarm becomes ineffective. Models are available that also offer back-up battery power. Remember to replace your CO detectors at least every five years and change the batteries every fall, when you change the time on your clocks.