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Consumer Protection Safety Commission Document #4466
THE HAZARD
What is carbon monoxide (CO) and how is it produced in the
home?
CO is a colorless, odorless, toxic gas. It is produced by the
incomplete combustion of solid, liquid and gaseous fuels. Appliances
fueled with gas, oil, kerosene, or wood may produce CO. If such
appliances ar not installed, maintained, and used properly, CO
may accumulate to dangerous levels.
What are the symptoms of CO poisoning and why are these symptoms
particularly dangerous?
Breathing CO causes symptoms such as headaches, dizziness, and
weakness in healthy people. CO also causes sleepiness, nausea,
vomiting, confusion and disorientation. At very high levels, it
causes loss of consciousness and death.
This is particularly dangerous because CO effects often are not
recognized. CO is odorless and some of the symptoms of CO poisoning
are similar to the flu or other common illnesses.
Are some people more affected by exposure to CO than others?
CO exposures especially affect unborn babies, infants, and people
with anemia or a history of heart disease. Breathing low levels
of the chemical can cause fatigue and increase chest pain in people
with chronic heart disease.
THE DATA
How many people die from CO poisoning each year?
In 1989, the most recent year for which statistics are available,
thee were about 220 deaths from CO poisoning associated with gas-fired
appliances, about 30 CO deaths associated with solid-fueled appliances
(including charcoal grills), and about 45 CO deaths associated
with liquid- fueled heaters.
How many people are poisoned from CO each year?
Nearly 5,000 people in the United States are treated in hospital
emergency rooms for CO poisoning; this number is believed to be
an underestimate because many people with CO symptoms mistake
the symptoms for the flu or are misdiagnosed and never get treated.
CO PREVENTION
How can production of dangerous levels of CO be prevented?
Dangerous levels of CO can be prevented by proper appliance maintenance,
installation, and use:
Maintenance
A qualified service technician should check your home's central
and room heating appliances (including water heaters and gas dryers)
annually. The technician should look at the electrical and mechanical
components of appliances, such as thermostat controls and automatic
safety devices.
- Chimneys and flues should be checked for blockages, corrosion,
and loose connections.
- Individual appliances should be serviced regularly. Kerosene
and gas space heaters (vented and unvented) should be cleaned
and inspected to insure proper operation.
- CPSC recommends finding a reputable service company in the
phone book or asking your utility company to suggest a qualified
service technician.
Installation
Proper installation is critical to the safe operation of combustion
appliances. All new appliances have installation instructions
that should be followed exactly. Local building codes should be
followed as well.
- Vented appliances should be vented properly, according to
manufacturer's instructions.
- Adequate combustion air should be provided to assure complete
combustion.
- All combustion appliances should be installed by professionals.
Appliance Use
- Follow manufacturer's directions for safe operation.
- Make sure the room where an unvented gas or kerosene space
heater is used is well ventilated; doors leading to another
room should be open to insure proper ventilation.
- Never use an unvented combustion heater overnight or in a
room where you are sleeping.
Are there signs that might indicate improper appliance operation?
Yes, these are:
- Decreasing hot water supply
- Furnace unable to heat house or runs constantly
- Sooting, especially on appliances
- Unfamiliar or burning odor Increased condensation inside
windows
Are there visible signs that might indicate a CO problem?
Yes, these are:
- Improper connections on vents and chimneys
- Visible rust or stains on vents and chimneys
- An appliance that makes unusual sounds or emits an unusual
smell
- An appliance that keeps shutting off (Many new appliances
have safety components attached that prevent operation if an
unsafe condition exists. If an appliance stops operating, it
may be because a safety device is preventing a dangerous condition.
Therefore, don't try to operate an appliance that keeps shutting
off; call a service person instead.)
Are there other ways to prevent CO poisoning?
Yes, these are:
- Never use a range or oven to heat the living areas of the
home
- Never use a charcoal grill or hibachi in the home
- Never keep a car running in an attached garage
CO DETECTION
Can CO be detected?
Yes, CO can be detected with CO detectors that meet the requirements
of Underwriters Laboratories (UL) standard 2034.
Since the toxic effect of CO is dependent upon both CO concentration
and length of exposure, long-term exposure to a low concentration
can produce effects similar to short term exposure to a high concentration.
Detectors that meet the UL standard measure both high CO concentrations
over short periods of time and low CO concentrations over long
periods of time. The effects of CO can be cumulative over time
Detectors sound an alarm before the level of CO in a person's
blood would become crippling
Detectors that meet the UL 2034 standard currently cost between
$35 and $80.
Where should the detector be installed?
CO gases distribute evenly and fairly quickly throughout the
house; therefore, a CO detector should be installed on the wall
or ceiling in sleeping area/s but outside individual bedrooms
to alert occupants who are sleeping.
Aren't there safety devices already on some appliances? And
if so, why is a CO detector needed?
Vent safety shutoff systems have been required on furnaces and
vented heaters sine the late 1980s. They protect against blocked
or disconnected vents or chimneys.
Oxygen depletion sensors (ODS) have also been installed on unvented
gas space heaters since the 1980s. ODS protect against the production
of CO caused by insufficient oxygen for proper combustion.
These devices (ODSs and vent safety shutoff systems) are not
a substitute for regular professional servicing, and many older,
potentially CO-producing appliances may not have such devices.
Therefore, a CO detector is still important in any home as another
line of defense.
Are there other CO detectors that are less expensive?
There are inexpensive cardboard or plastic detectors that change
color and do not sound an alarm and have a limited useful life.
They require the occupant to look at the device to determine if
CO is present. CO concentrations can build up rapidly while occupants
are asleep, and these devices would not sound an alarm to wake
them.
CONSUMER PROTECTION SAFETY COMMISSION'S ROLE
- CPSC worked closely with UL to develop a safety standard for
CO detectors (UL 2034).
- CPSC embarked on an extensive public awareness campaign in
1993 to reach consumers and educate them about CO through the
media. Activities included a message from President Clinton
declaring the last week of September "CO Safety Awareness Week."
- CPSC also developed stories for television, radio, and newspapers,
as well as brochures and posters for consumers.
- CPSC is proposing that the national model building code organizations
include a provision for the installation of state of the art
CO detectors in all new residential construction. The proposal
calls for installation in sleeping areas, but outside individual
bedrooms.
- Under CPSC's proposal, battery-operated units would be allowed
only in existing homes, not new construction. Even homes with
no permanently-installed fuel-burning appliances would have
to install them because CO deaths have been associated with
the use of portable kerosene heaters, wood-burning stoves, charcoal
grills wrongly used indoors, and auto fumes from an attached
garage.
- CPSC staff is working with state and local code jurisdictions
to incorporate CO detector requirements into state and local
legislation.
- CPSC is working with the National Fire Protection Association
to develop a national installation standard.
CO DETECTOR REQUIREMENTS IN THE U.S.
- On September 15, 1993, Chicago, IL became one of the first
cities in the nation to adopt an ordinance requiring the installation
of CO detectors that bear the mark of a nationally-recognized
testing laboratory in all new single-family homes and in existing
single-family residences that are being equipped with new oil
or gas combustion furnaces.
- Kingston, NY has approved a code to require the installation
of CO detectors in multiple dwellings with four or more dwelling
units.
- Bel Air, TX requires CO detectors in some single-family dwellings.
- The Recreational Vehicle Industry Association (RVIA) requires
CO detectors in motor homes made after September 1, 1993. RVIA
requires CO detectors in all recreational vehicles that are
motorized and in towable recreational vehicles that have a generator
or are prepped for a generator. RVIA's membership includes approximately
90% of all U.S. recreational vehicle manufacturers.
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