What You Need To Know About The Leading Cause Of Poisoning Deaths In
America

CARBON MONOXIDE

WHAT IS CARBON MONOXIDE AND WHO IS AT RISK?

Carbon monoxide (CO) is a colorless, odorless deadly gas. Because
you can't see, taste or smell it, carbon monoxide can kill you before
you know it's there.

Everyone is at risk for carbon monoxide poisoning. Experts
believe, however, that individuals with greater oxygen requirements such
as unborn babies, infants, children, senior citizens and people with
coronary or respiratory problems are at greater risk.

WHY IS CARBON MONOXIDE SO DANGEROUS?

The great danger of carbon monoxide is its attraction to hemoglobin
in the bloodstream. When breathed in, carbon monoxide replaces the
oxygen which cells need to function. When CO is present in the air, it
rapidly accumulates in the blood, causing symptoms similar to the flu,
such as headaches, fatigue, nausea, dizzy spells, confusion and
irritability. As levels increase, vomiting, loss of consciousness and
eventually brain damage or death can result.

WHERE DOES CARBON MONOXIDE COME FROM?

Carbon monoxide is a by-product of combustion, present whenever
fuel is burned. It is produced by common home appliances, such as gas
or oil furnaces, gas refrigerators, gas clothes dryers, gas ranges, gas
water heaters or space heaters, fireplaces, charcoal grills and wood
burning stoves. Fumes from automobiles and gas powered lawn mowers also
contain carbon monoxide and can enter a home through walls or doorways
if an engine is left running in an attached garage.

All of these sources can contribute to a CO problem in the home. If
a home is vented properly and is free from appliance malfunctions, air
pressure fluctuations or airway blockages, carbon monoxide will most
likely be safely vented to the outside. But in today's
"energy-efficient" homes this is frequently not the case. Tightly
constructed/sealed homes can trap CO-polluted air in a home year-round.
Furnace heat exchangers can crack, vents can become blocked, inadequate
air supply for combustion appliances can cause conditions known as
backdrafting or reverse stacking, which force contaminated air back into
the home. Exhaust fans on range hoods, clothes dryers and bathroom fans
can also pull combustion products into the home.

HOW CAN I PROTECT MYSELF AND MY FAMILY FROM CARBON MONOXIDE POISONING?

The Consumer Product Safety Commission (CPSC) recommends installing
at least one carbon monoxide detector per household, near the sleeping
area. Additional detectors on every level of a home and in every
bedroom provide extra protection. Choose an Underwriters Laboratories
Inc. (UL) listed detector that sounds an audible alarm. You can choose
a model that is wired to your home's electrical system, a model which
plugs into a standard electrical outlet, or a battery operated model.
Battery operated carbon monoxide detectors continue to protect even in
the event of a power outage. Hardwired AC models, although more costly
and difficult to install, reduce the expense of battery replacement but
do not offer protection during power outages. Hardwired AC models with
battery back-up offer double protection.

Gas appliances should be serviced yearly by a qualified service
technician. Stove burners should be cleaned and adjusted to minimize
the amount of carbon monoxide produced. Before making changes to a
house that might affect the ventilation of fuel burning appliances,
contact your heating contractor. When replacing heating appliances,
purchase appliances designed to reduce dangers from carbon monoxide,
such as sealed combustion gas furnaces, direct vent gas fireplaces, or
induced draft gas water heaters. Electric powered heating appliances do
not produce carbon monoxide.

If your carbon monoxide detector sounds, first make sure it is your
CO detector and not your smoke detector. The latest generation of
carbon monoxide detectors listed with UL will be marked "carbon monoxide
detector" in a contrasting color on the cover. Some detectors feature a
warning alarm which will sound before the full (continuous) alarm. If
your detector is in warning alarm, carbon monoxide is beginning to
accumulate. It is important to locate and eliminate the source of CO
before the condition worsens. A trained HVAC contractor or appliance
service technician can inspect your home to determine the cause of
carbon monoxide build-up.

If your detector is in full alarm and any member of the household
is experiencing symptoms of poisoning, call your local fire department
immediately! Remember that infants and children may be affected more
quickly by carbon monoxide. Be sure to see if they are exhibiting
symptoms. If no one is feeling symptoms, ventilate the home with fresh
air, turn off all potential sources of carbon monoxide and have a
qualified technician inspect your combustion appliances.

In addition to installing carbon monoxide detectors, consumers
should regularly inspect and service potential problem sources of carbon
monoxide.

CHECKLIST - WHERE TO LOOK FOR PROBLEM SOURCES OF CARBON MONOXIDE:

Furnaces are frequently the source of leaks and should be carefully
inspected. Have a professional check the following:

* Measure the concentration of CO in the flue gases.

* Check furnace connections to flue pipes and venting systems to
outside of the home for signs of corrosion, rust, gaps or
holes.

* Check furnace filters and filtering systems for dirt or
blockages.

* Check forced air fans for proper installation and correct air
flow of flue gases. Improper furnace blower installation can
result in carbon monoxide build-up because toxic gas is blown
into rather than out of the house.

* Check the combustion chamber and internal heat exchanger for
cracks, metal fatigue or corrosion - be sure they are clean
and free of debris.

* Check burners and ignition system. A flame that is mostly
yellow in color in natural gas-fired furnaces is often a sign
fuel is not burning completely and higher levels of carbon
monoxide are being released. Oil furnaces with similar
problems can give off an "oily" odor. Remember, you can't
smell carbon monoxide.

Check all venting systems to the outside, including flues and
chimneys for proper design and installation, cracks, corrosion,
holes, debris or blockages. Animals and birds can build nests in
chimneys, preventing gases from escaping.

Check all other appliances that use flammable fuels such as natural
gas, oil, wood or kerosene.

* Appliances include water heaters, clothes dryers, kitchen
ranges, ovens or cooktops, wood burning stoves, gas
refrigerators. * Pilot lights can be a source of carbon
monoxide because the by-products of combustion are released
inside the home rather than vented to the outside. Gas ovens
and ranges should be monitored closely.

Be sure space heaters are vented properly. Unvented space heaters
that use a flammable fuel such as kerosene can release carbon
monoxide into the home.

Barbecue grills should never be operated indoors, nor should stove
tops or ovens that operate on flammable fuels ever be used to heat
a residence.

Check fireplaces for closed, blocked or bent flues, soot and
debris.

Check the clothes dryer vent opening outside the house for lint.

If initial testing does not confirm the presence of carbon monoxide,
there may be several reasons:

Testing equipment used to measure the presence of carbon monoxide
in the air must be calibrated to sense low levels of gas
concentration.

* Some detection devices only measure concentrations of 1,000
parts per million and higher, significantly above safe levels.
Testing equipment should be capable of sensing levels as low
as one part per million. For example, Underwriters
Laboratories' standard for residential carbon monoxide
detectors requires detectors to alarm before 90 minutes of
exposure to 100 parts per million of carbon monoxide.

* If initial readings don't reveal sufficient concentrations of
carbon monoxide to set off the alarm, digital measurement
testing equipment that produces a printed 24-hour record can
be used to help identify the source.

If doors or windows are left open or appliances are turned off and
outside air enters the home, carbon monoxide can dissipate. This
creates a lower reading than the level that triggered the alarm.

* To help assure proper measurement, carbon monoxide readings
should be conducted as soon as possible after an alarm
incident.

If appliances, flues and chimneys are confirmed to be in good
working order, the source of carbon monoxide leaks may be from
backdrafting.

This condition exists primarily in tightly sealed/constructed
homes. Flue gases normally vent to the outside through flues and
chimneys. Air pressure inside a tightly sealed home may become
lower than outside, causing outside air to flow into the house
through vents and chimneys.

Inadequate air supply in a room where two or more combustion-driven
appliances share the same air source, such as a water heater and
furnace in a utility closet, can create a more complicated form of
backdrafting called reverse stacking.

* This occurs when one appliance, such as the furnace, turns on
and is unable to get adequate fresh air. When the furnace
operates, it then draws contaminated air from the water heater
exhaust and spreads polluted air throughout the house.

Note: Because carbon monoxide accumulates in some detectors over time,
as it does in the bloodstream, the source of CO may be appliances that
were running before the alarm sounded.

A sticking thermostat can keep the furnace running continually,
depleting the oxygen supply inside the house. This can lead to
backdrafting.

In multiple family dwellings where living spaces share walls and
pipes, carbon monoxide from one unit may enter a neighboring space
through floor boards, cracks or underneath doors.

If a home has an attached garage, carbon monoxide produced by car
exhaust can leak into the house. This is especially a problem for
home mechanics who may run the car engine frequently for periods of
time - even if the garage door is left open.

This booklet has been prepared as a public service by First Alert@ in
cooperation with the Cooperative State Research, Education and Extension
Service (CSREES) of the U.S. Department of Agriculture.

Potential Carbon Monoxide Sources in the Home

If you have questions about carbon monoxide, contact your local gas
utility, a qualified heating contractor, or the Extension Services
office listed in the white pages of your phone book.

@1995 BRK Brands, Inc.

CM904