Carbon Monoxide Questions and
- What is carbon monoxide (CO) and how is it produced in the home?
Carbon monoxide (CO) is a colorless, odorless, poisonous gas. It is
produced by the incomplete burning of solid, liquid, and gaseous fuels.
Appliances fueled with natural gas, liquified petroleum (LP gas), oil,
kerosene, coal, or wood may produce CO. Burning charcoal produces CO.
Running cars produce CO.
- How many people are unintentionally poisoned by CO?
Every year, over 200 people in the United States die from CO produced
by fuel-burning appliances (furnaces, ranges, water heaters, room
heaters). Others die from CO produced while burning charcoal inside a
home, garage, vehicle or tent. Still others die from CO produced by cars
left running in attached garages. Several thousand people go to hospital
emergency rooms for treatment for CO poisoning. (A more recent review claims
CO as the leading cause of more than 15,000 accidental poisoning deaths
in the United States each year and another 10,000 injuries according to the
Carbon Monoxide Medical Association)
- What are the symptoms of CO poisoning?
The initial symptoms of CO poisoning are similar to the flu (but
without the fever). They include:
- Shortness of breath
Many people with CO poisoning mistake their symptoms for the flu or
are misdiagnosed by physicians, which sometimes results in tragic
- What should you do to prevent CO poisoning?
- Make sure appliances are installed according to manufacturer's
instructions and local building codes. Most appliances should be
installed by professionals. Have the heating system (including chimneys
and vents) inspected and serviced annually. The inspector should also
check chimneys and flues for blockages, corrosion, partial and complete
disconnections, and loose connections.
- Install a CO detector/alarm that meets the requirements of the
current UL standard 2034 or the requirements of the IAS 6-96 standard. A
carbon monoxide detector/alarm can provide added protection, but is no
substitute for proper use and upkeep of appliances that can produce CO.
Install a CO detector/alarm in the hallway near every separate sleeping
area of the home. Make sure the detector cannot be covered up by
furniture or draperies.
- Never burn charcoal inside a home, garage, vehicle, or tent.
- Never use portable fuel-burning camping equipment inside a home,
garage, vehicle, or tent.
- Never leave a car running in an attached garage, even with the
garage door open.
- Never service fuel-burning appliances without proper knowledge,
skills, and tools. Always refer to the owner's manual when performing
minor adjustments or servicing fuel-burning appliances.
- Never use gas appliances such as ranges, ovens, or clothes dryers
for heating your home.
- Never operate un-vented fuel-burning appliances in any room with
closed doors or windows or in any room where people are sleeping.
- Do not use gasoline-powered tools and engines indoors. If use is
unavoidable, ensure that adequate ventilation is available and whenever
possible place engine unit to exhaust outdoors.
- What CO level is dangerous to your health?
The health effects of CO depend on the level of CO and length of
exposure, as well as each individual's health condition. The
concentration of CO is measured in parts per million (ppm). Health
effects from exposure to CO levels of approximately 1 to 70 ppm are
uncertain, but most people will not experience any symptoms. Some heart
patients might experience an increase in chest pain. As CO levels
increase and remain above 70 ppm, symptoms may become more noticeable
(headache, fatigue, nausea). As CO levels increase above 150 to 200 ppm,
disorientation, unconsciousness, and death are possible.
- What should you do if you are experiencing symptoms of CO
If you think you are experiencing any of the symptoms of CO
poisoning, get fresh air immediately. Open windows and doors for more
ventilation, turn off any combustion appliances, and leave the house.
Call your fire department and report your symptoms. You could lose
consciousness and die if you do nothing. It is also important to contact
a doctor immediately for a proper diagnosis. Tell your doctor that you
suspect CO poisoning is causing your problems. Prompt medical attention
is important if you are experiencing any symptoms of CO poisoning when
you are operating fuel-burning appliances. Before turning your
fuel-burning appliances back on, make sure a qualified serviceperson
checks them for malfunction.
- What has changed in CO detectors/alarms recently?
CO detectors/alarms always have been and still are designed to alarm
before potentially life-threatening levels of CO are reached. The UL
standard 2034 (2002 revision) has stricter requirements that the
detector/alarm must meet before it can sound. As a result, the
possibility of nuisance alarms is decreased.
- What should you do when the CO detector/alarm sounds?
Never ignore an alarming CO detector/alarm. If the detector/alarm
sounds: Operate the reset button. Call your emergency services (fire
department or 911). Immediately move to fresh air -- outdoors or by an
- How should a consumer test a CO detector/alarm to make sure it is
Consumers should follow the manufacturer's instructions. Using a test
button, some detectors/alarms test whether the circuitry as well as the
sensor which senses CO is working, while the test button on other
detectors only tests whether the circuitry is working. For those units
which test the circuitry only, some manufacturers sell separate test
kits to help the consumer test the CO sensor inside the alarm.
- What is the role of the U.S. Consumer Product Safety Commission (CPSC)
in preventing CO poisoning?
CPSC worked closely with Underwriters Laboratories (UL) to help
develop the safety standard (ANSI/UL 2034-02) for CO detectors/alarms. CPSC
helps promote carbon monoxide safety awareness to raise awareness of CO
hazards and the need for regular maintenance of fuel-burning appliances.
CPSC recommends that every home have a CO detector/alarm that meets the
requirements of the most recent UL standard 2034 or the IAS 6-96
standard in the hallway near every separate sleeping area. CPSC also
works with industry to develop voluntary and mandatory standards for
- Do some cities require that CO detectors/alarms be installed?
On September 15, 1993, Chicago, Illinois became one of the first
cities in the nation to adopt an ordinance requiring, effective October
1, 1994, the installation of CO detectors/alarms in all new
single-family homes and in existing single-family residences that have
new oil or gas furnaces. Several other cities also require CO
detectors/alarms in apartment buildings and single-family dwellings.
- Should CO detectors/alarms be used in motor homes and other
CO detectors/alarms are available for boats and recreational vehicles
and should be used. The Recreation Vehicle Industry Association requires
CO detectors/alarms in motor homes and in tow-able recreational vehicles
that have a generator or are prepped for a generator.
U.S. Consumer Product
Office of Information and
Washington, DC 20207