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Carbon Monoxide
"The Silent Killer"
What
is Carbon Monoxide (CO)
Why
is it so dangerous?
Where
does it come from?
How
can I protect myself and my family?
Checklist
for possible sources of Carbon Monoxide
What is Carbon Monoxide?
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. It is a by-product of combustion.
At lower levels of exposure,
carbon monoxide may cause numerous health problems.
Because you can't see, taste or smell it, carbon monoxide
can kill you before you know it's there. Carbon
Monoxide is so hard to detect and so deadly, it has earned
the nick-name "The Silent Killer".
Symptoms
of CO poisoning may be as follows:
-
Slight
headache and dizziness
-
Nausea
-
Drowsiness
and an euphoric feeling
-
Confusion
and irritability
-
Unconsciousness
-
Death
Because the
symptoms of Carbon Monoxide poisoning are so common (nausea,
dizziness, headaches, etc.) CO poisoning are often
misdiagnose, even by health care professionals. Everyone
is at risk for carbon monoxide poisoning. Some individuals
may be more vulnerable to poisoning though, such as unborn
babies, infants, children, senior citizens and people with
heart of lung problems.
Why
is it so dangerous?
The
great danger of carbon monoxide is its attraction to
hemoglobin in the bloodstream, which normally carries
life-giving oxygen to cells and tissues. As even small
amounts are breathed in, carbon monoxide quickly bonds with
hemoglobin in the blood, displacing the oxygen that organs
need to function. When CO is present in the air, it rapidly
accumulates in the blood, forming a toxic compound known as carboxyhemoglobin
(COHb).
The
result is an increased heart rate as your heart tries to get
more oxygen to your brain and other vital organs. As the CO level in your blood increases, the amount
of oxygen transported to your body's cells decreases. It is
this oxygen deprivation that makes Carbon Monoxide so
deadly. Sensitive parts of your body like your nervous
system, brain, heart, and lungs suffer the most from a lack
of oxygen. The CO displaces the oxygen on your hemoglobin
because the COHb bond is over 200 times stronger than
oxygen's bond with your hemoglobin. The strong COHb bond
also makes it difficult for your body to eliminate CO
buildups from your bloodstream. Because this buildup takes
longer to get rid of
Carbon Monoxide can poison you slowly over a period of
several hours, even in low concentrations. It continues to
accumulate in the bloodstream as long as you are exposed to
it.
The symptoms of long term exposure to
low concentrations of carbon monoxide will cause symptoms
similar to the flu, such as headaches, fatigue, nausea,
dizziness, weakness, drowsiness, sleepiness, vomiting and
diarrhea. Other symptoms may also include any of the
following: burning eyes, redness of the skin, confusion and
irritability, loss of muscle control, chest tightness, heart
fluttering. As levels increase, vomiting, loss of
consciousness and eventually brain damage and ultimately
death can result.
People who suspect they have been
exposed to carbon monoxide, should immediately seek fresh
air and if symptoms linger, they should see their doctor
quickly. Unconscious victims should be moved outdoors. Call
for medical assistance and until it arrives, keep those
exposed lying down and keep them warm by wrapping them in
blankets. Rest is absolutely necessary. If breathing has ceased, artificial
respiration (CPR) should be undertaken immediately after
removing the victim to fresh air. Even good meaning rescuers
can easily become victims themselves if they (you) are
exposed to the same conditions.
Carbon monoxide poisoning should
be suspected if more than one member of the family is sick
and if they feel better after being away from home for a
period of time.
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Where does it come from?
Carbon
monoxide is a common by-product of combustion, present
whenever fossil fuels are burned. It is produced by
malfunctioning or unvented gas or oil home appliances such
as furnaces, clothes dryers, ranges, ovens, water heaters
and space heaters, as well as fireplaces, charcoal grills, wood burning
stoves and cigarette smoke. 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.
Avoid running these types of devices while
indoors, including gas barbecues. All of these
sources can contribute to a CO problem in the home.
Usually,
carbon monoxide is vented safely to the outside. However,
insulation meant to keep indoor air warm during the winter
or cool in the summer can help trap CO-polluted air in the
home. Furnace heat exchangers can crack; vents can become blocked,
vents and chimneys
may reverse direction causing a downdraft, which traps
combustion gases in the home. 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 my family?
The
Consumer Product Safety Commission (CPSC) recommends
installing at least one carbon monoxide alarm with an
audible warning signal near the sleeping area. Additional
detectors on every level of a home and in every bedroom
provide extra protection. Carbon monoxide detectors all use
special sensors to detect the presence of Carbon Monoxide.
The most accurate and dependable type of sensor for
detecting Carbon Monoxide is an) electrochemical sensor;
the number one choice of fire departments worldwide. Choose an
Underwriters Laboratories Inc. (UL) listed alarm that sounds
an audible warning. Look for the UL logo on the package. 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. Hard wired
AC models, although more costly and difficult to install,
reduce the expense of battery replacement but do not offer
protection during power outages. Hard wired AC models with
battery back-up offer double protection. Like smoke
detectors, battery operated units should be tested weekly
while hard wired systems should be tested monthly.
The
International Association of Fire Chiefs (IAFC) also
recommends UL listed carbon monoxide alarms on every level
of the home and in areas near appliances that are potential
sources of CO. Look for the IAFC logo of the package when
you select an alarm.
In
addition to installing carbon monoxide alarms as a first line of defense,
residents should have a qualified professional check all fuel burning
appliances, furnaces, venting and chimney systems at least once a year or as
recommended by the manufacturer. Gas burning equipment which is out of
adjustment often has a flickering yellow flame as opposed to a steady blue
flame. If you see this, call a qualified service person. 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. Note: Electric powered
heating appliances do not produce carbon monoxide.
A simple test is to hold a burning
match to the edge of the draft hood on a water heater or a
conventional furnace. This will give an indication of draft.
It is common for some products of combustion to leak out
into the basement when a piece of equipment starts, however
after it has been running for a minute, good draft should be
established and the smoke from a lit match will be drawn into the exhaust
if the draft is good. A flame being blown downwards or out
into the room indicates a dangerously bad draft.
When products of combustion cannot
escape properly from the house, there tends to be a build up
of moisture within the exhaust flue and ultimately within
the house. Look for rusting on flue pipes and water leaking
from the base of the chimney. Look for moisture condensing
on windows and in extreme cases, on walls near the furnace.
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.
Call your local fire department immediately and evacuate
everyone from the house. Remember that because carbon
monoxide is colorless and odorless, never ignore an alarm
even if you feel no adverse symptoms. Remember that infants,
children, and pets may be affected more quickly by carbon
monoxide. Be sure to monitor them more closely for
exhibiting symptoms.
Once the fire department arrives, they
will first try and determine if your carbon monoxide
detector is working properly and if it is, determine the
extent of carbon monoxide present with a device called a
carbon monoxide gas monitor. Although, not every fire
department has such a device. If such a device is not
available, a trained HVAC contractor or appliance service
technician should be notified to inspect your home to
determine the cause of carbon monoxide build-up. Until such
a technician can be located, the home should be ventilated
with fresh air, all potential sources of carbon monoxide
should be turned off and you should have a complete
knowledge of the symptoms of carbon monoxide and monitor
everyone for such symptoms.
It is possible that your carbon
monoxide detector may be faulty or just need a new battery
if it is not electrically supplied. Caution must be used in
determining whether or not the detector is in fact working
properly.
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Checklist
for where to look for possible sources of Carbon Monoxide
Furnaces are frequently the source of
leaks and should be carefully inspected. Have a professional
check the following:
-
Check the combustion chamber and
internal heat exchanger for cracks, metal fatigue or
corrosion - be sure they re clean and free of debris.
-
Gas ovens or ranges should never be
used to heat a room. During winter, many residents insulate
windows and doors to prevent drafts. Prolonged use of a gas
oven or portable heater in an insulated area will diminish
the supply of oxygen and generate carbon monoxide that can
reach lethal levels.
-
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 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 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 other appliances that use
flammable fuels such as natural gas, oil, wood or kerosene.
Appliances include water heaters, clothes dryers, kitchen
ranges, ovens or cook tops, 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.
-
Check fireplaces for
closed, blocked or bent flues, soot and debris.
-
Check the clothes dryer vent opening
outside the house for lint, which can block the vent and
force carbon monoxide back inside.
-
Charcoal should never be used
indoors, especially in a fireplace. Its burning emits high
carbon monoxide levels.
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