|InspectUSA.com - Does Your Smoke Detector Really Work?
There has been a reduction in
fire deaths and injuries resulting from the widespread use of smoke detectors.
Despite this increased presence of detectors, there are still thousands each
year who die or suffer painful, disfiguring injuries as a result of fires in
their homes. The United States has been identified as a world leader in many
respects. Unfortunately, we also lead the industrialized world in home fire
casualties. It has been estimated that smoke detectors reduce the risk of dying
in a house fire by at least 50%, but only if the smoke detector is working.
Sixteen million smoke
detectors in U.S. homes don't work based on a
recent 1994-95 survey conducted as part of the "National Smoke Detector
Project." This means that more than one of every four homes equipped with smoke
detectors is literally at risk in the event of a fire. In fact, the government
report shows that there are more homes that have smoke detectors that don't work
than there are homes that don't have detectors at all.
Why are there so many
defective smoke detectors? According to the government investigators, it is
Batteries were found to be dead or
The detector's vents were clogged
with dirt, dust, or grease.
The sensing chamber was infested by
important than the reasons identified for this serious problem is what can be
done about it. The solution is simple enough: Test the detector regularly.
Every smoke detector's user manual emphasizes the need for doing so. The
National Fire Protection Association recommends that battery-powered detectors
be tested weekly, and that those powered by household current be tested
monthly. Indeed, the Association each year promotes "National Fire Prevention
Week," during the first week of October. Typical is the Association's theme for
1996: "Let's Hear it for Fire Safety - Test Your Detectors!"
isn't testing being done? Why aren't homeowners following these
important recommendations? After all, the claim is made, simply
press the test button on the detector. If the alarm sounds, then, it
is claimed, you can be sure that your detector will give you and
your family the early warning you need in order to exit safely and avoid a
|To gain a
better understanding of this serious problem, it is necessary to examine
the assumptions underlying the "test button test." The correct
location for the smoke detector, according to fire experts, is on the
ceiling in the center of the room. But the ceiling height in most homes is
eight feet from the floor. This means that unless the homeowner is a
professional basketball player, he or she must stand on a chair or on some
other elevation. Here are some practical considerations: How many
homeowners are going to make the effort every week to drag a chair or
stool over to the smoke detector? What about the elderly or the
infirm? What about those who are wheelchair bound? What about
the millions of smoke detectors without test buttons?
|In view of these
considerations, some have asked, why not use a broomstick to press the test
button? The answer: Repeated jabbing of the test button with this clumsy object
will soon force displacement of the test button from its contacts or otherwise
damage it. Indeed, in its 1994 report on smoke detector operability, the
Government report found detectors with damaged components suggesting that, at
least in some instances, homeowners were following these ill-advised
suggestions. Then, too, the test button recess in many types of smoke detectors
has a diameter smaller than that of a broomstick, effectively preventing the
button from being depressed by this means. Finally, it is literally impossible
to use a broomstick to press the button on wall mounted units.
|What of the test button
itself? Does it signal a valid test? The alarm goes off when you press the
test button. Okay. Does that mean it will always give the alarm in the event of
a fire? That it will respond to the presence of smoke? The government
investigators found, on the contrary, that the "test button test" does not
always signify that the detector will sound in the event of a fire. A number of
smoke detectors were found to have their vents clogged with dust, dirt or
grease; in other instances, insects had infested the sensing chamber. In all
such cases, smoke did not activate the alarm but the test button nevertheless
caused the alarm to sound.
then, is the best way of testing smoke detectors? The simplest, easiest way of
doing so is by using an aerosol product that has been tested and approved by a
recognized testing facility like Underwriters Labs. Home Safeguard Industries
makes such a product. Indeed, it was the first of its kind and has become the
world standard for the testing of smoke detectors of all kinds.
Smoke Detector Tester was used in the
government survey referred to in this article because it was found to be
reliable, effective and easy to use.
government investigators followed the simple instructions on the can's
label: "Spray the smoke detector for one to two seconds from a distance of
two to four feet." That's how they found that 16 million smoke
detectors in U.S. homes don't work.
If you, too, follow these
simple instructions, you will quickly learn whether your smoke detector will
warn you in the event of the "real thing." If , following the spraying, your
smoke detector goes into alarm, you can be sure that it will do its job in the
event of a fire in your home. If the alarm does not go off, chances are you have
a defective detector.
Here's what to do if the
alarm doesn't sound:
- Make sure the power source is connected
and/or the battery is still good.
- Check the vents of the detector for dirt,
dust, grease, or spider webs. If present, clean with a dry cloth and a
A smoke detector has
probably been damaged and will not operate if it has been painted over. Also,
an older detector - say, 10 years old - is likely to have corroded contacts or
otherwise faulty electronics, causing the alarm to go off too late, too soon, or
not at all. Under any of these circumstances, the detector is not doing the job
it was designed to do. It should be replaced. After all, according to one
estimate, a smoke detector that has been in operation for 10 years has gone
through more than 3.5 million monitoring cycles. And detectors these days are
not that expensive, especially considering your family's safety.
In the event of
replacement, what kind of detector should you have in your home?
There are two kinds of
detectors on the market today, ionization and photoelectric. Ionization
detectors have a quantity of radioactive material in the sensing chamber which
throws off a constant stream of radioactive particles. This action creates an
electric charge in the chamber. When smoke enters the chamber, it reduces the
electric charge. When the electric charge falls below a preset amount, the
alarm, is initiated. Photoelectric smoke detectors, on the other hand, have a
beam of light inside of their sensing chamber. When the beam is broken up or
deflected the alarm is sounded.
Of the two types of smoke
detectors, the ionization type is by far the most common. More than three of
every four detectors in U.S. homes today are ionization detectors, according to
the government report. The reason is simple: They are much less expensive than
photoelectric detectors. But ionization detectors have a serious downside: they
are prone to nuisance, or false, alarms. Indeed, the ionization technology
itself is the problem. Ionization devices are designed to detect advance
particles of combustion, causing the detector to respond to the most minute
airborne particles. Routine kitchen activities, including cooking and dish
washing, can cause the alarm to sound, as can spraying windows with conventional
window cleaners. An ionization detector near a bathroom may sound the alarm
when you are showering or bathing.
The super-sensitivity of
ionization detectors is why many detectors in the government study were found to
have missing batteries. Homeowners simply removed the batteries, thus sparing
themselves the constant annoyance of the alarm's sounding during daily
To add to the ionization
problem, these detectors contain a radioactive substance, Americium 241, a by
product of the production of plutonium. To be sure, the radioactive substance
involved is small, but there are tens of millions of this kind of detector in
U.S. homes now, with more being added daily. This simply aggravates problems
related to the disposal of radioactive materials, which we in the U.S. and,
indeed, the world, face on a daily basis.
To adequately protect your
family and home you should take the following steps:
Install working smoke detectors at each
level of your home. Among other locations, they should be placed in the
immediate vicinity of the sleeping areas.
Smoke detectors of choice should be the
photoelectric type and be powered by household current and contain a
battery backup. This allows your detector to operate even in the event
of a power outage.
Test your detectors with
Smoke Detector Tester.
Replace detectors more than 10 years old.
Install a photoelectric detector in the
kitchen, where most home fires start.
Here's what smoke detector
manufacturers should do:
Okay the testing of their smoke detectors
with Smoke Detector Tester.
Mount an educational campaign, alerting
the public to the fact that smoke detectors do wear out. In this
campaign, manufacturers should enlist the aid of the National Fire
Protection Association, insurance companies and fire departments.
Trade-ins should be offered as a further inducement to replace old
Phase out the manufacture of ionization
detectors for the home, concentrating their production efforts on the
photoelectric type, preferably those powered by household current, with
a battery backup. This will reduce the nuisance alarm problem related
to the ionization devices.
Rewrite users' manuals with the objective
of making these documents simple and easy to read, augmented by good
Does Your Smoke Detector Really Function Properly?