Smoke Detectors: The Forgotten Life Insurance
By Jim Rooney
Smoke detectors are probably the single greatest life saving device invented for the home in the last 35 years. They have been part of the building code for at least that long, and the statistics compiled each year show that when they work they save lives, and when they don't work, people die.
The US has about 40,000 house fires per year—the highest of the industrialized nations—and fatalities occur. Smoke alarms have lowered the death to fire ratio dramatically, but, they have to work to do any good.
Human Error Costs Lives
Frequently, you'll read about a fire in which someone perished, and then you'll come across a statement along the lines of "Smoke detectors were present, but the batteries had been removed..." or "Smoke detectors were present, but authorities were unable to determine if they operated."
The lack of a battery in a smoke detector during a fire investigation is sometimes explainable. It could signal that the battery had started to weaken, and the alarm was sending out that steady but intermittent beeping noise to alert the occupants. In turn, they may have become annoyed with the sound and pulled the battery out to stop the noise.
There are some detectors with such a low threshold of alarm, they are set off anytime someone cooks a slice of toast—so out comes the battery to shut it up. Or worse yet, the battery came out to replace a battery in some other device, such as a toy or a TV remote.
These situations are completely avoidable, senseless, and are the types of incidents that cause fire fighters to shake their heads and mutter in wonderment at the fatal mistakes of their fellow citizens.
Failure Rates of Smoke Detectors
Smoke detectors installed into the house wiring have batteries in them as back-up power supplies in the event part of the fire situation involves electrical service interruption.
It's when the investigators can't find the actual cause of smoke detector failure that things get sticky, so again we have to rely upon statistics.
When you spread any sort of electrical or mechanical device out over millions upon millions of the same thing, you are going to come up with something called a failure rate. Some are just not going to work right out of the box, while others will last a generation.
The Canadians did some studies in the early 1990s and came up with some interesting numbers. They discovered that 3% of all smoke detectors are likely fail in the first year of deployment. That's a pretty small number—unless it's the one in your house.
Keep in mind that failure means it doesn't do what it's supposed to do, and that is to alert you of a possible fire so that you can get out and save your life. That's serious business.
The researchers also noted that smoke detectors tend to either work or not, and don't slowly fail. When they fail, they fail, like a light bulb, on one minute and out the next.
With only 1 smoke detector in the home, even the miniscule 3% failure rate could be a disaster. That's one reason why smoke detectors are installed in small groups, such as 3 in your home, with one guarding the other.
It is now recommended smoke detectors are placed in each bedroom. Why? Statistics indicate if the fire starts inside of a bedroom, and the door to the room is closed and the smoke detector is on the ceiling out in the hall, the person sleeping in that room is not likely to survive to hear the smoke detector go off. Gruesome, isn't it?
Smoke detector failure rates climb to a point where at 30 years of age, almost all smoke detectors fail. At about age 15, the chances that it won't work are dead even. That places the failure rate at age 10 at 30%. Professionals feel this is the best time for replacement.
Many installed smoke detectors are candidates for replacement now—past age 10—so I recommend that you go ahead and do it. Even the "hard wired" ones aren't all that difficult to replace.
WARNING: Remember to locate which breaker in your electrical panel controls the detectors, and be sure that the power is off to them before you attempt to remove them.
One of the newest smoke detector technologies on the market is smoke detectors with sealed batteries designed to last the whole 10 years. When the battery dies, you throw it out and get a new one. I'm sure the failure rate percentages hold for these as well, so never rely upon just one.
Functioning smoke detectors are the cheapest form of life insurance you can buy.