What is carbon monoxide?

Carbon monoxide, or CO, is an odorless, colorless gas that can cause sudden illness and death. The use of alternative sources of fuel or electricity for heating, cooling or cooking can cause CO to build up in a home, garage or camper and poison the people and animals inside.

Where is CO found?

CO is found in combustion fumes, such as those produced by cars and trucks, small gasoline engines, 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.

What are the symptoms of CO poisoning?

The most common symptoms of CO poisoning are headache, dizziness, weakness, nausea, vomiting, chest pain and confusion. High levels of CO ingestion can cause loss of consciousness and death.

Unless suspected, CO poisoning can be difficult to diagnose because the symptoms mimic other illnesses. People who are sleeping or intoxicated can die from CO poisoning before ever experiencing symptoms.

How does CO poisoning occur?

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. This blocks oxygen from getting into the body, which can damage tissues and result in death.

Who is at risk from CO poisoning?

All people and animals are at risk for CO poisoning. Certain groups — unborn babies, infants and people with chronic heart disease, anemia or respiratory problems — are more susceptible to its effects.

Each year, more than 500 Americans die from unintentional CO poisoning, and more than 2,000 commit suicide by intentionally poisoning themselves.

How can I prevent CO poisoning in my home?

Do have your heating system, water heater and any other gas, oil, or coal burning appliances serviced by a qualified technician every year.

Do install a battery-operated CO detector in your home and check or replace the battery when you change the time on your clocks each spring and fall. If the detector sounds, leave your home immediately and call 911.

Do get fresh air immediately and seek prompt medical attention if you suspect CO poisoning and are feeling dizzy, light-headed or nauseous.

Do purchase gas equipment that carries the seal of a national testing agency, such as the American Gas Association or Underwriters’ Laboratories.

Do vent all gas appliances so that CO will not build up.

Do have your chimney checked or cleaned every year. Chimneys can be blocked by debris. This can cause CO to build up inside your home.

Do make sure horizontal vent pipes to fuel appliances are not perfectly level. Indoor vent pipes should go up slightly as they go toward outdoors. This helps prevent CO or other gases from leaking if the joints or pipes aren’t fitted tightly.

Don’t use a generator, charcoal grill, hibachi, lantern, camp stove or other gasoline or charcoal-burning device inside your home, basement or garage or near a window.

Don’t burn anything in a stove or fireplace that isn’t vented.

Don’t heat your house with a gas oven.

Don’t use portable flameless chemical heaters (catalytic) indoors. Although these heaters don’t have a flame, they burn gas and can cause CO to build up inside your home.

Don’t patch a vent pipe with tape, gum or something else. This kind of patch can make CO build up in your home.

Can I heat my house safely or cook when the power is out?

Don’t 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.

Don’t use a charcoal grill or a barbecue grill indoors. Using a grill indoors will cause a build up of CO inside your home.

Don’t burn charcoal indoors. Burning charcoal — red, gray, black, or white — gives off CO.

Don’t use a portable gas camp stove indoors. Using a gas camp stove indoors can cause CO to build up inside your home.

Don’t use a generator inside your home, basement, or garage or near a window, door, or vent.

How can I avoid CO poisoning from my vehicle?

Do have a mechanic check the exhaust system of your car every year. A small leak in your car’s exhaust system can lead to a build up of CO inside the car.

Do open vents or windows when driving with your tailgate down to make sure air is moving through your car. If only the tailgate is open CO from the exhaust will be pulled into the car.

Don’t run a car or truck in a garage with the garage door shut. CO can build up quickly while your car or truck is running in a closed garage. Always open the garage door to let in fresh air.

Other Important CO Poisoning Prevention Tips

Do seek shelter with friends or at a community shelter if conditions in your home are too hot or too cold and your power or gas isn’t working.

Don’t 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.

Don’t run a motor vehicle, generator, pressure washer or any gasoline-powered engine outside an open window, door, or vent where exhaust can vent into an enclosed area.

Educational Materials

• Flyers and door hangers www.cdc.gov/disasters/co-materials.html
• Public Service Announcements www.cdc.gov/co/psa.htm
• CO Poisoning Prevention Guidelines www.cdc.gov/co/guidelines.htm

For more information, visit www.bt.cdc.gov/disasters/carbonmonoxide.asp, or call CDC at 800-CDC-INFO (English and Spanish) or 888-232-6348 (TTY).