Facts and Definition of Carbon Monoxide Poisoning
- Carbon monoxide (sometimes referred to as CO) is a colorless, odorless gas produced by burning material containing carbon. Carbon monoxide poisoning can cause brain damage and death. You can't see it, smell it, or taste it; but carbon monoxide can kill you.
- Because carbon monoxide is an odorless, tasteless, and colorless gas, it is known as the "silent killer."
- Carbon monoxide is produced by common household appliances. When not properly ventilated, carbon monoxide emitted by these appliances can build up. See the list of appliances that can emit carbon monoxide in this article under Carbon Monoxide Poisoning Causes.
- Early symptoms of carbon monoxide poisoning such as headaches, nausea, and fatigue, are often mistaken for the flu because the deadly gas goes undetected in a home. Prolonged exposure can lead to brain damage and even death.
Carbon Monoxide Poisoning Causes
Carbon monoxide is formed when organic compounds burn. The most common sources are motor vehicle exhaust, smoke from fires, engine fumes, and nonelectric heaters. Carbon monoxide poisoning is often associated with malfunctioning or obstructed exhaust systems and with suicide attempts.
Sources of carbon monoxide:
- Gas water heaters
- Kerosene space heaters
- Charcoal grills
- Propane heaters and stoves
- Gasoline and diesel powered generators
- Cigarette smoke
- Propane-fueled forklifts
- Gasoline powered concrete saws
- Indoor tractor pulls
- Boats engines
- Spray paint, solvents, degreasers, and paint removers
- Smoke inhalation from a wildfire
Risks for exposure to carbon monoxide include
- Children riding in the back of enclosed pickup trucks (particularly high risk)
- Industrial workers at pulp mills, steel foundries, and plants producing formaldehyde or coke (a hard grey fuel)
- Personnel at fire scenes
- Using heating sources or electric generators during power outages
- Those working indoors with combustion engines or combustible gases
- Swimming near or under the stern or swim-step of a boat with the boat engine running
- Back drafting when a boat is operated at a high bow angle
- Mooring next to a boat that is running a generator or engine
- Improper boat ventilation
Carbon Monoxide Poisoning Symptoms and Signs
Exposure to carbon monoxide is most commonly accompanied by the following symptoms:
Carbon Monoxide Poisoning and Smoke Inhalation Symptoms
Carbon monoxide is one of the byproducts from burning items and other materials during a fire; and it's the leading cause of death from smoke inhalation due to a fire. Even cigarette smoke is a source of carbon monoxide.
Signs and symptoms that you've inhaled too much smoke include:
- Shortness of breath
- Hoarseness or noisy breathing
- Irritated eyes
When to Seek Medical Care
If you or someone you know have any of the signs and symptoms of carbon monoxide poisoning, go to a hospital emergency department immediately, particularly if several people in the household are affected, or if pets are affected as well.
Carbon Monoxide Poisoning Diagnosis
Because signs and symptoms of carbon monoxide poisoning are not specific, a blood test to look for it is the most effective way to make the diagnosis.
Carbon Monoxide Poisoning Self-Care at Home
Move all family members and pets to fresh air away from the source of carbon monoxide (CO).
No home therapy is available for carbon monoxide poisoning.
Seek medical care in a hospital emergency department.
Carbon Monoxide Poisoning Treatment
The treatment for carbon monoxide poisoning is high-dose oxygen, usually using a facemask attached to an oxygen reserve bag.
Carbon monoxide levels in the blood may be periodically checked until they are low enough to safely send the patient home.
In severe poisoning, if available, a hyperbaric pressure chamber may be used to provide even higher doses of oxygen to the patient.
It is important to find the source of the carbon monoxide. A local fire department or public service company will help find the source of carbon monoxide and make sure the building is safe.
Carbon Monoxide Poisoning Prevention
The best protection from carbon monoxide poisoning is to install a carbon monoxide alarm on each level of your home or boat as your first line of defense. A carbon monoxide monitor with an audible alarm works much like a home smoke alarm and beeps loudly when the sensors detect carbon monoxide.
If the alarm sounds, evacuate the building. People who have symptoms of carbon monoxide poisoning should seek emergency medical care. Call the fire department or public service company to investigate.
Inspect your home for hazards.
Your home heating system, chimney, and flue must be inspected and cleaned by a qualified technician every year. Keep chimneys clear of bird and squirrel nests, leaves, and residue to ensure proper ventilation.
Be sure your furnace and other appliances, such as gas ovens, ranges, and cook tops, are inspected for adequate ventilation.
Do not burn charcoal inside your house (even in the fireplace). Have gas fireplaces inspected each fall to ensure the pilot light burns safely.
Do not operate gasoline-powered engines in confined areas such as garages or basements. Do not leave a car, mower, generator, or other vehicle running in an attached garage, even with the door open.
Do not block or seal shut exhaust flues or ducts for appliances such as water heaters, ranges, and clothes dryers.
Become familiar with the hazards of carbon monoxide poisoning and boating (please see Web Links section).
Some states in the US require carbon monoxide poison detectors in homes, boats, day care centers, businesses, etc. For a list of states that require carbon monoxide detectors, please read the Carbon Monoxide Detectors State Statues to see if you are in compliance.
Carbon Monoxide Poisoning Prognosis
The prognosis for a person with carbon monoxide poisoning is difficult to predict.
Death can result from severe cases.
Even with proper treatment, some people develop long-term brain damage, resulting in complications such as severe memory loss, difficulty thinking, or other neurologic or psychiatric problems.
Others appear to have no long-term problems.
Reviewed on 11/17/2017
Medically reviewed by Avrom Simon, MD; Board Certified Preventative Medicine with Subspecialty in Occupational Medicine
CDC.gov. Carbon Monoxide Poisoning FAQs.
Hampson NB. Residential carbon monoxide alarm use: opportunities for poisoning prevention. J Environ Health. 2011 Jan-Feb;73(6):30-3.
Johnson-Arbor, K., et al. A survey of residential carbon monoxide detector utilization among Connecticut Emergency Department patients. Clin Toxicol (Phila). 2012 Jun;50(5):384-9.
National Fire Protection Association. Fast Facts About Smoke Alarms and Fire.