Carbon monoxide (CO) is a gas that has no odor or color. But it is very dangerous. It can cause sudden illness and death. CO is found in combustion fumes, such as those made by cars and trucks, lanterns, stoves, gas ranges and heating systems. CO from these fumes can build up in places that don't have a good flow of fresh air. You can be poisoned by breathing them in. The most common symptoms of CO poisoning are:

• Headache
• Dizziness
• Weakness
• Nausea
• Vomiting
• Chest pain
• Confusion

It is often hard to tell if someone has CO poisoning, because the symptoms may be like those of other illnesses. People who are sleeping or intoxicated can die from CO poisoning before they have symptoms. A CO detector can warn you if you have high levels of CO in your home.

Definition

Carbon monoxide (CO) is a colorless, practically odorless, and tasteless gas or liquid. It results from incomplete oxidation of carbon in combustion.  Burns with a violet flame.  Slightly soluble in water; soluble in alcohol and benzene.  Specific gravity 0.96716;  boiling point -190^oC; solidification point -207^oC; specific volume 13.8 cu. ft./lb. (70^oF).  Auto ignition temperature (liquid) 1128^oF.  Classed as an inorganic compound.
Source:  "The Condensed Chemical Dictionary," 9th ed., revised by Gessner G. Hawley, Van Nostrand Reinhold Co., NY, 1977.

Sources of Carbon Monoxide

Unvented kerosene and gas space heaters; leaking chimneys and furnaces; back-drafting from furnaces, gas water heaters, wood stoves, and fireplaces; gas stoves; generators and other gasoline powered equipment; automobile exhaust from attached garages; and tobacco smoke.  Incomplete oxidation during combustion in gas ranges and unvented gas or kerosene heaters may cause high concentrations of CO in indoor air.  Worn or poorly adjusted and maintained combustion devices (e.g., boilers, furnaces) can be significant sources, or if the flue is improperly sized, blocked, disconnected, or is leaking.  Auto, truck, or bus exhaust from attached garages, nearby roads, or parking areas can also be a source.

Health Effects Associated with Carbon Monoxide

At low concentrations, fatigue in healthy people and chest pain in people with heart disease. At higher concentrations, impaired vision and coordination; headaches; dizziness; confusion; nausea. Can cause flu-like symptoms that clear up after leaving home. Fatal at very high concentrations.  Acute effects are due to the formation of carboxyhemoglobin in the blood, which inhibits oxygen intake.  At moderate concentrations, angina, impaired vision, and reduced brain function may result.  At higher concentrations, CO exposure can be fatal.

Silence isn’t always golden, especially when it comes to carbon monoxide (CO) poisoning. CO is an odorless, colorless gas that can cause sudden illness and death. When power outages occur after severe weather, such as winter storms or hurricanes, using alternative sources of power can cause CO to build-up in a home and poison the people and animals inside. The most common symptoms of CO poisoning are headache, dizziness, weakness, nausea, vomiting, chest pain, and confusion. High levels of CO inhalation can cause loss of consciousness and death.

There are steps you can take to help protect yourself and your household from CO poisoning. Change or check the batteries in your CO detector every six months. If you don’t have a battery-powered or battery back-up CO detector, buy one soon.

CO is found in fumes produced by furnaces, stoves, lanterns, and gas ranges, or by burning charcoal and wood. CO from these sources can build up in enclosed or partially enclosed spaces. People and animals in these spaces can be poisoned and can die from breathing CO.

Key Facts

• Every year, at least 430 people die in the U.S. from accidental CO poisoning.
• Approximately 50,000 people in the U.S. visit the emergency department each year due to accidental CO poisoning.
• Red blood cells pick up CO quicker than they pick up oxygen.
• When you inhale CO, your body replaces the oxygen in blood with CO.
• People who are sleeping or who have been drinking alcohol can die from CO poisoning before ever having symptoms.

Red Blood Cells

Red blood cells pick up CO quicker than they pick up oxygen. If there is a lot of CO in the air, the body may replace oxygen in blood with CO.

Don’t Run a Car Inside a Garage

Don't run a car or truck inside a garage attached to your house, even if you leave the door open.

Severe Weather

When power outages occur after severe weather (such as winter storms, hurricanes, or tornadoes), using alternative sources of power can cause CO to build-up in a home and poison the people and animals inside.

Campers

CO is found in combustion fumes, such as those produced by stoves, lanterns, burning charcoal and wood, and gas ranges and heating systems. CO from these sources can build up in enclosed or semi-enclosed spaces. People and animals in these spaces can be poisoned by breathing it.

Boating

Larger boats sometimes have generators that vent toward the rear of the boat. This venting poses a danger of CO poisoning to people on the rear swim deck or water platform. CO builds up above the water near the water platform.

Gas Flame

Each year, more than 400 Americans die from unintentional CO poisoning, more than 20,000 visit the emergency room and more than 4,000 are hospitalized due to CO poisoning.

CO Poisoning Prevention Tips

• Never use a gas range or oven to heat a home.
• Never leave the motor running in a vehicle parked in an enclosed or partially enclosed space, such as a garage.
• Never run a generator, pressure washer, or any gasoline-powered engine inside a basement, garage, or other enclosed structure, even if the doors or windows are open, unless the equipment is professionally installed and vented. Keep vents and flues free of debris, especially if winds are high. Flying debris can block ventilation lines.
• Never run a motor vehicle, generator, pressure washer, or any gasoline-powered engine less than 20 feet from an open window, door, or vent where exhaust can vent into an enclosed area.
• Never use a charcoal grill, hibachi, lantern, or portable camping stove inside a home, tent, or camper.
• If conditions are too hot or too cold, seek shelter with friends or at a community shelter.
• If CO poisoning is suspected, consult a health care professional right away.

What is Carbon Monoxide?

Carbon monoxide, or “CO,” is an odorless, colorless gas that can kill you.

Where is CO found?

CO is found in fumes produced any time you burn fuel in cars or trucks, small engines, stoves, lanterns, grills, fireplaces, gas ranges, or furnaces. CO can build up indoors and poison people and animals who breathe it.

What are the symptoms of CO poisoning?

The most common symptoms of CO poisoning are headache, dizziness, weakness, upset stomach, vomiting, chest pain, and confusion. CO symptoms are often described as “flu-like.” If you breathe in a lot of CO it can make you pass out or kill you. People who are sleeping or drunk can die from CO poisoning before they have symptoms.

Who is at risk from CO poisoning?

Everyone is at risk for CO poisoning. Infants, the elderly, people with chronic heart disease, anemia, or breathing problems are more likely to get sick from CO. Each year, more than 400 Americans die from unintentional CO poisoning not linked to fires, more than 100,000 visit the emergency room, and more than 14,000 are hospitalized.

How can I prevent CO poisoning in my home?

• Install a battery-operated or battery back-up CO detector in your home. Check or replace the detector’s battery when you change the time on your clocks each spring and fall. Place your detector where it will wake you up if it alarms, such as outside your bedroom. Consider buying a detector with a digital readout. This detector can tell you the highest level of CO concentration in your home in addition to alarming. Replace your CO detector every five years.
• Have your heating system, water heater, and any other gas, oil, or coal burning appliances serviced by a qualified technician every year.
• Do not use portable flameless chemical heaters indoors.
• If you smell an odor from your gas refrigerator have an expert service it. An odor from your gas refrigerator can mean it could be leaking CO.
• When you buy gas equipment, buy only equipment carrying the seal of a national testing agency, such as Underwriters’ Laboratories.
• Make sure your gas appliances are vented properly. Horizontal vent pipes for appliances, such as a water heater, should go up slightly as they go toward outdoors, as shown below. This prevents CO from leaking if the joints or pipes aren’t fitted tightly.
• Have your chimney checked or cleaned every year. Chimneys can be blocked by debris. This can cause CO to build up inside your home or cabin.
• Never patch a vent pipe with tape, gum, or something else. This kind of patch can make CO build up in your home, cabin, or camper.
• Never use a gas range or oven for heating. Using a gas range or oven for heating can cause a build up of CO inside your home, cabin, or camper.
• Never burn charcoal indoors. Burning charcoal – red, gray, black, or white – gives off CO.
• Never use a portable gas camp stove indoors. Using a gas camp stove indoors can cause CO to build up inside your home, cabin, or camper.
• Never use a generator inside your home, basement, or garage or less than 20 feet from any window, door, or vent.
• When using a generator, use a battery-powered or battery backup CO detector in your home.

How can I avoid CO poisoning from my car or truck?

• Have a mechanic check the exhaust system of your car or truck every year. A small leak in the exhaust system can lead to a build up of CO inside the car.
• Never run your car or truck inside a garage that is attached to a house even with the garage door open. Always open the door to a detached garage to let in fresh air when you run a car or truck inside.
• If you drive a car or SUV with a tailgate, when you open the tailgate open the vents or windows to make sure air is moving through. If only the tailgate is open CO from the exhaust will be pulled into the car or SUV.

Levels in Homes

Average levels in homes without gas stoves vary from 0.5 to 5 parts per million (ppm). Levels near properly adjusted gas stoves are often 5 to 15 ppm and those near poorly adjusted stoves may be 30 ppm or higher.

Steps to Reduce Exposure to Carbon Monoxide

It is most important to be sure combustion equipment is maintained and properly adjusted.  Vehicular use should be carefully managed adjacent to buildings and in vocational programs.  Additional ventilation can be used as a temporary measure when high levels of CO are expected for short periods of time.

• Keep gas appliances properly adjusted.
• Consider purchasing a vented space heater when replacing an unvented one.
• Use proper fuel in kerosene space heaters.
• Install and use an exhaust fan vented to outdoors over gas stoves.
• Open flues when fireplaces are in use.
• Choose properly sized wood stoves that are certified to meet EPA emission standards. Make certain that doors on all wood stoves fit tightly.
• Have a trained professional inspect, clean, and tune-up central heating system (furnaces, flues, and chimneys) annually. Repair any leaks promptly.
• Do not idle the car inside garage.

Measurement Methods

Some relatively high-cost infrared radiation adsorption and electrochemical instruments do exist.  Moderately priced real-time measuring devices are also available.  A passive monitor is currently under development.

Standards or Guidelines

No standards for CO have been agreed upon for indoor air.  The U.S. National Ambient Air Quality Standards for outdoor air are 9 ppm (40,000 micrograms per meter cubed) for 8 hours, and 35 ppm for 1 hour.

Because CO is odorless, colorless, and otherwise undetectable to the human senses, people may not know that they are being exposed. The initial symptoms of low to moderate CO poisoning are similar to the flu (but without the fever). They include:

• Headache
• Fatigue
• Shortness of breath
• Nausea
• Dizziness

High level CO poisoning results in progressively more severe symptoms, including:

• Mental confusion
• Vomiting
• Loss of muscular coordination
• Loss of consciousness
• Ultimately death

Symptom severity is related to both the CO level and the duration of exposure. For slowly developing residential CO problems, occupants and/or physicians can mistake mild to moderate CO poisoning symptoms for the flu, which sometimes results in tragic deaths. For rapidly developing, high level CO exposures (e.g., associated with use of generators in residential spaces), victims can rapidly become mentally confused, and can lose muscle control without having first experienced milder symptoms; they will likely die if not rescued. 

 If you suspect you are being subjected to carbon monoxide poisoning get fresh air immediately. Open windows and doors for more ventilation, turn off any combustion appliances, and leave the house. You could lose consciousness and die from carbon monoxide poisoning if you do nothing. It is also important to contact a doctor IMMEDIATELY for a proper diagnosis. Remember to tell your doctor that you suspect carbon monoxide poisoning is causing your problems. Prompt medical attention is important.

Remember that some symptoms from combustion pollutants - headaches, dizziness, sleepiness, coughing, and watery eyes - may also occur because of common medical problems. These medical problems include colds, the flu, or allergies. Similar symptoms may also occur because of other indoor air pollutants. Contact your doctor for a proper diagnosis.

To help your doctor make the correct diagnosis, try to have answers to the following questions:

• Do your symptoms occur only in the home? Do they disappear or decrease when you leave home, and reappear when you return?
• Is anyone else in your household complaining of similar symptoms, such as headaches, dizziness, or sleepiness? Are they complaining of nausea, watery eyes, coughing, or nose and throat irritation?
• Do you always have symptoms?
• Are your symptoms getting worse?
• Do you often catch colds or get the flu?
• Are you using any combustion appliances in your home?
• Has anyone inspected your appliances lately? Are you certain they are working properly?

Your doctor may take a blood sample to measure the level of carbon monoxide in your blood if he or she suspects carbon monoxide poisoning. This sample will help determine whether carbon monoxide is affecting your health.

Contact qualified appliance service people to have your appliances inspected and adjusted if needed. You should be able to find a qualified person by asking your appliance distributor or your fuel supplier. In some areas, the local fuel company may be able to inspect and adjust the appliance.

CO poisoning is entirely preventable. Protect yourself and your family by learning the symptoms of CO poisoning and how to prevent it.

When winter temperatures plummet and home heating systems run for hours the risk of carbon monoxide (CO) poisoning increases.

Every year, at least 420 people die in the U.S. from accidental CO poisoning. More than 100,000 people in the U.S. visit the emergency department each year due to accidental CO poisoning. There are steps you can take to help protect yourself and your household from CO poisoning.

CO is found in fumes produced by furnaces, kerosene heaters, vehicles “warmed up” in garages, stoves, lanterns, and gas ranges, portable generators, or by burning charcoal and wood. CO from these sources can build up in enclosed or partially enclosed spaces. People and animals in these spaces can be poisoned and can die from breathing CO.

How to Recognize CO Poisoning

The most common symptoms of CO poisoning are headache, dizziness, weakness, nausea, vomiting, chest pain, and confusion. People who are sleeping or who have been drinking alcohol can die from CO poisoning before ever having symptoms.

CO Poisoning Prevention Tips

• Check or change the batteries in your CO detector every six months. If you don’t have a battery-powered or battery back-up CO detector, buy one soon.
• Have your heating system, water heater and any other gas, oil, or coal burning appliances serviced by a qualified technician every year.
• Keep vents and flues free of debris. Debris can block ventilation lines.
• Never leave the motor running in a vehicle parked in an enclosed or partially enclosed space, such as a garage.
• Never run a motor vehicle, generator, pressure washer, or any gasoline-powered engine less than 20 feet from an open window, door, or vent where exhaust can vent into an enclosed area.
• Never use a charcoal grill, hibachi, lantern, or portable camping stove inside a home, tent, or camper.
• Never run a generator, pressure washer, or any gasoline-powered engine inside a basement, garage, or other enclosed structure, even if the doors or windows are open.
• If you suspect CO poisoning, call 911 or a health care professional right away.

CO poisoning is entirely preventable. You can protect yourself and your family by learning the symptoms of CO poisoning and how to prevent it.

Carbon monoxide (CO) is an odorless, colorless gas that kills without warning. It claims the lives of hundreds of people every year and makes thousands more ill. Many household items including gas- and oil-burning furnaces, portable generators, and charcoal grills produce this poison gas. Following these important steps can keep your family safe.

CO Detectors

• Install battery-operated or battery back-up CO detectors near every sleeping area in your home.
• Check CO detectors regularly to be sure they are functioning properly.

Oil & Gas Furnaces

• Have your furnace inspected every year.

Portable Generators

• Never use a generator inside your home or garage, even if doors and
  windows are open.
• Only use generators outside, more than 20 feet away from your home, doors, and windows.

• Have your home heating systems (including chimneys and vents) inspected and serviced annually by a trained service technician.
• Never use portable generators inside homes or garages, even if doors and windows are open. Use generators outside only, far away from the home.
• Never bring a charcoal grill into the house for heating or cooking. Do not barbeque in the garage.
• Never use a gas range or oven for heating.
• Open the fireplace damper before lighting a fire and keep it open until the ashes are cool. An open damper may help prevent build-up of poisonous gases inside the home.
• Install battery-operated CO alarms or CO alarms with battery backup on every level of the home and outside sleeping areas. Interconnected CO alarms are best; when one sounds, they all sound. 
• Know the symptoms of carbon monoxide poisoning: headache, dizziness, weakness, nausea, vomiting, sleepiness, and confusion. If you suspect CO poisoning, get outside to fresh air immediately, and then call 911.

When Your Furnace Kicks On, Be Sure Poison Gas Isn’t Coming Out

Every winter when the temperature drops, your furnace can become a silent killer. Gas- and oil-burning furnaces produce carbon monoxide (CO). CO is an invisible, odorless, poison gas that kills hundreds every year and makes thousands more sick. Follow these steps to keep your family safe this winter.

Oil & Gas Furnaces

• Have your furnace inspected every year.

CO Detectors

• Install battery-operated or battery back-up CO detectors near every sleeping area in your home.
• Check CO detectors regularly to be sure they are functioning properly.

When the Power Goes Out, Keep Your Generator Outside

Portable back-up generators produce the poison gas carbon monoxide (CO). CO is an odorless, colorless gas that kills without warning. It claims the lives of hundreds of people every year and makes thousands more ill. Follow these steps to keep your family safe.

PORTABLE GENERATORS

• Never use a generator inside your home or garage, even if doors and windows are open.
• Only use generators outside, more than 20 feet away from your home, doors, and windows.

CO DETECTORS

• Install battery-operated or battery back-up CO detectors near every sleeping area in your home.
• Check CO detectors regularly to be sure they are functioning properly.

Daylight Saving Time ends Sunday, November 6. As you prepare to set your clocks back one hour, remember to check the batteries in your carbon monoxide (CO) detector. If you don’t have a battery-powered or battery back-up CO alarm, now is a great time to buy one. More than 400 people die each year in the United States from unintentional, non-fire related CO poisoning.

CO is found in fumes produced by furnaces, vehicles, generators, stoves, lanterns, gas ranges, or burning charcoal or wood. CO from these sources can build up in enclosed or partially enclosed spaces. People and animals in these spaces can be poisoned and can die from breathing CO.

When power outages occur during emergencies, such as ice storms or other severe weather, the use of alternative sources of power for heating or cooking can cause CO to build up in a home, garage, or camper and to poison the people and animals inside.

You Can Prevent Carbon Monoxide Exposure

Do

• Have your heating system, water heater and any other gas, oil, or coal burning appliances serviced by a qualified technician every year.
• Install a battery-operated or battery back-up CO detector in your home and check or replace the battery when you change the time on your clocks each spring and fall.
• Leave your home immediately and call 911 if your CO detector ever sounds. Seek prompt medical attention if you suspect CO poisoning and are feeling dizzy, light-headed, or nauseated.

Don’t

• Run a car or truck inside a garage attached to your house, even if you leave the door open.
• Burn anything in a stove or fireplace that isn’t vented.
• Heat your house with a gas oven.
• Use a generator, charcoal grill, camp stove, or other gasoline or charcoal-burning device inside your home, basement, or garage or outside less than 20 feet from a window, door, or vent.

CO poisoning is entirely preventable. You can protect yourself and your family by learning the symptoms of CO poisoning and acting wisely during a power outage.

Each floor of the home needs a separate detector. If you are getting a single carbon monoxide detector, place it near the sleeping areas and make certain the alarm is loud enough to wake you up. 

How do I install my CO alarm?

Follow the installation instructions found in the manufacturer's use and care booklet that accompanies the product. Proper installation is an important factor in receiving optimum performance. It's important to follow these instructions exactly.

Do CO alarms operate differently than smoke alarms?

Although they may look and sound similar, CO alarms and smoke alarms are designed and intended to detect two separate, distinct hazards. Therefore, to help protect your family from both hazards, it's important to install both UL Listed CO alarms and smoke detectors.

How do I take care of my CO alarm?

Like smoke detectors, CO alarms need to be tested regularly and cleaned as indicated in the manufacturer's use and care booklet. If the unit operates off a battery, test the detector weekly and replace the battery at least once a year.

Should I follow any safety tips for using and maintaining my CO alarms?

As with any product, read the manufacturer's use and care booklet for installation and maintenance guidelines. Keep these instructions on file for future reference.

If your unit operates off the battery, never allow anyone to "borrow" the battery. Like any appliance or power tool, a CO alarm can't work unless it has a functioning power source.

What is carbon monoxide (CO) and how is it produced?

Carbon monoxide (CO) is a deadly, colorless, odorless, poisonous gas. It is produced by the incomplete burning of various fuels, including coal, wood, charcoal, oil, kerosene, propane, and natural gas. Products and equipment powered by internal combustion engines such as portable generators, cars, lawn mowers, and power washers also produce CO.

How many people are unintentionally poisoned by CO?

On average, about 170 people in the United States die every year from CO produced by non-automotive consumer products. These products include malfunctioning fuel-burning appliances such as furnaces, ranges, water heaters and room heaters; engine-powered equipment such as portable generators; fireplaces; and charcoal that is burned in homes and other enclosed areas. In 2005 alone, CPSC staff is aware of at least 94 generator-related CO poisoning deaths. Forty-seven of these deaths were known to have occurred during power outages due to severe weather, including Hurricane Katrina. Still others die from CO produced by non-consumer products, such as cars left running in attached garages. The Centers for Disease Control and Prevention estimates that several thousand people go to hospital emergency rooms every year to be treated for CO poisoning.

What are the symptoms of CO poisoning?

Because CO is odorless, colorless, and otherwise undetectable to the human senses, people may not know that they are being exposed. The initial symptoms of low to moderate CO poisoning are similar to the flu (but without the fever). They include:

• Headache
• Fatigue
• Shortness of breath
• Nausea
• Dizziness

High level CO poisoning results in progressively more severe symptoms, including:

• Mental confusion
• Vomiting
• Loss of muscular coordination
• Loss of consciousness
• Ultimately death

Symptom severity is related to both the CO level and the duration of exposure. For slowly developing residential CO problems, occupants and/or physicians can mistake mild to moderate CO poisoning symptoms for the flu, which sometimes results in tragic deaths. For rapidly developing, high level CO exposures (e.g., associated with use of generators in residential spaces), victims can rapidly become mentally confused, and can lose muscle control without having first experienced milder symptoms; they will likely die if not rescued.

How can I prevent CO poisoning?

• Make sure appliances are installed and operated according to the manufacturer's instructions and local building codes. Most appliances should be installed by qualified professionals. Have the heating system professionally inspected and serviced annually to ensure proper operation. The inspector should also check chimneys and flues for blockages, corrosion, partial and complete disconnections, and loose connections.
• Never service fuel-burning appliances without proper knowledge, skill and tools. Always refer to the owners manual when performing minor adjustments or servicing fuel-burning equipment.
• Never operate a portable generator or any other gasoline engine-powered tool either in or near an enclosed space such as a garage, house, or other building. Even with open doors and windows, these spaces can trap CO and allow it to quickly build to lethal levels.
• Install a CO alarm that meets the requirements of the current UL 2034 safety standard. A CO alarm can provide some added protection, but it is no substitute for proper use and upkeep of appliances that can produce CO. Install battery-operated CO alarms or CO alarms with battery backup on every level of the home and outside sleeping areas. Interconnected CO alarms are best; when one sounds, they all sound. Make sure the alarm cannot be covered up by furniture or draperies.
• Never use portable fuel-burning camping equipment inside a home, garage, vehicle or tent unless it is specifically designed for use in an enclosed space and provides instructions for safe use in an enclosed area.
• Never burn charcoal inside a home, garage, vehicle, or tent.
• Never leave a car running in an attached garage, even with the garage door open.
• Never use gas appliances such as ranges, ovens, or clothes dryers to heat your home.
• Never operate unvented fuel-burning appliances in any room where people are sleeping.
• Do not cover the bottom of natural gas or propane ovens with aluminum foil. Doing so blocks the combustion air flow through the appliance and can produce CO.
• During home renovations, ensure that appliance vents and chimneys are not blocked by tarps or debris. Make sure appliances are in proper working order when renovations are complete.

What CO level is dangerous to my health?

The health effects of CO depend on the CO concentration and length of exposure, as well as each individual's health condition. CO concentration is measured in parts per million (ppm). Most people will not experience any symptoms from prolonged exposure to CO levels of approximately 1 to 70 ppm but some heart patients might experience an increase in chest pain. As CO levels increase and remain above 70 ppm, symptoms become more noticeable and can include headache, fatigue and nausea. At sustained CO concentrations above 150 to 200 ppm, disorientation, unconsciousness, and death are possible.

What should I do if I am experiencing symptoms of CO poisoning and do not have a CO alarm, or my CO alarm is not going off?

If you think you are experiencing any of the symptoms of CO poisoning, get outside to fresh air immediately. Leave the home and call your fire department to report your symptoms from a neighbor’s home. You could lose consciousness and die if you stay in the home. 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. If the doctor confirms CO poisoning, make sure a qualified service person checks the appliances for proper operation before reusing them.

Are CO alarms reliable?

CO alarms always have been and still are designed to alarm before potentially life-threatening levels of CO are reached. The safety standards for CO alarms have been continually improved and currently marketed CO alarms are not as susceptible to nuisance alarms as earlier models.

How should a consumer test a CO alarm to make sure it is working?

Consumers should follow the manufacturer's instructions. Using a test button tests whether the circuitry is operating correctly, not the accuracy of the sensor. Alarms have a recommended replacement age, which can be obtained from the product literature or from the manufacturer.

How should I install a CO Alarm?

CO alarms should be installed according to the manufacturer's instructions. Install battery-operated CO alarms or CO alarms with battery backup on every level of the home and outside sleeping areas. Interconnected CO alarms are best; when one sounds, they all sound. CO alarms may be installed into a plug-in receptacle or high on the wall. Hard wired or plug-in CO alarms should have battery backup. Avoid locations that are near heating vents or that can be covered by furniture or draperies. CPSC does not recommend installing CO alarms in kitchens or above fuel-burning appliances.

What should you do when the CO alarm sounds?

Never ignore an alarming CO alarm! It is warning you of a potentially deadly hazard.

If the alarm signal sounds do not try to find the source of the CO:

• Immediately move outside to fresh air.
• Call your emergency services, fire department, or 911.
• After calling 911, do a head count to check that all persons are accounted for. DO NOT reenter the premises until the emergency services responders have given you permission. You could lose consciousness and die if you go in the home.
• If the source of the CO is determined to be a malfunctioning appliance, DO NOT operate that appliance until it has been properly serviced by trained personnel.

If authorities allow you to return to your home, and your alarm reactivates within a 24 hour period, repeat steps 1, 2 and 3 and call a qualified appliance technician to investigate for sources of CO from all fuel burning equipment and appliances, and inspect for proper operation of this equipment. If problems are identified during this inspection, have the equipment serviced immediately. Note any combustion equipment not inspected by the technician and consult the manufacturers’ instructions, or contact the manufacturers directly, for more information about CO safety and this equipment. Make sure that motor vehicles are not, and have not been, operating in an attached garage or adjacent to the residence.

What is the role of the U.S. Consumer Product Safety Commission (CPSC) in preventing CO poisoning?

CPSC staff worked closely with Underwriters Laboratories (UL) to help develop the safety standard (UL 2034) for CO alarms. CPSC helps promote carbon monoxide safety by raising awareness of CO hazards and the need for correct use and regular maintenance of fuel-burning appliances. CPSC staff also works with stakeholders to develop voluntary and mandatory standards for fuel-burning appliances and conducts independent research into CO alarm performance under likely home-use conditions.

Do some cities require that CO alarms be installed?

Many states and local jurisdictions now require CO alarms be installed in residences. Check with your local building code official to find out about the requirements in your location.

Should CO alarms be used in motor homes and other recreational vehicles?

CO alarms are available for boats and recreational vehicles and should be used. The Recreation Vehicle Industry Association requires CO alarms in motor homes and in trailers.