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Health Topics

Carbon Monoxide Poisoning

picture of a man installing a carbon monoxide detector Every year in the United States, more than 4,000 people are hospitalized and more than 400 die from unintentional carbon monoxide poisoning.

Every year thousands of people across the U.S. seek medical care for non-fatal CO poisoning.


view data about carbon monoxide


What is carbon monoxide?

Carbon monoxide, or CO is an odorless, colorless gas that is given off whenever fossil fuels are burned. Carbon monoxide is a poison, even at low levels, while carbon dioxide is a normal part of the breathing process. Breathing high levels of CO can cause severe illness or death in a matter of minutes.

Where is carbon monoxide found?

Carbon monoxide is found in combustion fumes, such as those made by cars and trucks, portable generators, wood-burning stoves, gas ranges and heating systems. CO from these fumes can build up in places that do not have a good flow of fresh air. Fumes with CO can also build up if heating systems are not maintained or vented properly.

Propane camp stoves, heaters, or propane lights also create fumes with CO. Carbon monoxide can build up if these camping supplies are used inside a tent. Boat engine exhaust and barbecue grills are other sources of carbon monoxide. Grills should not be used inside a garage or near windows.

What is carbon monoxide poisoning?

Carbon monoxide poisoning occurs by breathing in too much carbon monoxide. Inhaled carbon monoxide enters the lungs where it replaces oxygen in red blood cells and is then carried throughout the body. Symptoms of CO poisoning are similar to those experienced when there is too little oxygen in the air.

All people and animals are at risk for CO poisoning. Certain individuals, such as unborn babies, infants, and people with chronic heart disease, anemia, or respiratory problems, are more susceptible to its effects. Symptoms can vary from mild (fatigue, headache, dizziness, nausea) to severe (loss of consciousness and death). The level of exposure influences the damage done to an individual. Mental abilities can be impaired and permanent brain damage can occur.

Most people who survive CO poisoning recover fully. Studies have found, however, that 10 to 40 percent of survivors of severe carbon monoxide poisoning may have long-term health problems as a result of their exposure. Even minor and moderate cases of carbon monoxide poisoning indicate an underlying CO hazard in the patient’s home, work or recreational environment.

Exposure to moderate and high levels of CO over extended periods of time has also been linked to an increased risk of cardiovascular disease (CVD). The health effects of long - term exposure to low levels of CO are less well understood. Better tracking of CO poisoning and exposure may provide opportunities to learn about the effects of low-dose exposures.

How can carbon monoxide poisoning be prevented?

  • DO NOT burn anything in a stove or fireplace which is not vented, or may be clogged.
  • DO NOT run a car or truck inside a garage attached to your house, even if you leave the door open.
  • DO NOT sleep in any room with an unvented gas or kerosene space heater.
  • DO NOT use a generator, charcoal grill, camp stove, or other gasoline or charcoal-burning device inside your home, basement, or garage, near a window, or in a tent. Locate these devices at least 10 feet from your house with the exhaust facing away from the building.
  • DO NOT use a gas cooking range or oven to heat your home, even for a short time.
  • Have your heating system, water heater and any other gas, oil, or coal burning appliances serviced by a qualified technician every year. Repair leaks promptly.
  • Install CO detector(s) (battery-powered or electric with battery back-up) in your home, near the furnace and all sleeping areas. Replace the batteries when you change the time on your clocks each spring and fall, the same as for smoke detectors. If the alarm sounds, leave your home immediately and then call 911.
  • Make certain that doors on all wood stoves fit tightly.
  • Seek prompt medical attention if you suspect CO poisoning and are feeling dizzy, light-headed, or nauseous.

Where should carbon monoxide detectors be placed?

A CO detector should be centrally located outside each sleeping area in the immediate vicinity of the bedrooms. Each CO alarm should be located on the wall, ceiling or other location as specified in the manufacturer’s installation instructions that come with the unit.

For added protection, install additional CO detectors in each separate bedroom, and on every level of your home. Carbon monoxide detectors wear out. They need to be replaced about every five years. Expiration dates are provided by the manufacturer.

What data are included about carbon monoxide in New Hampshire’s Tracking program?

The available data related to carbon monoxide poisoning includes hospitalizations, emergency department visits and mortality.

view data about carbon monoxide

Where can I learn more about carbon monoxide?

New Hampshire Environmental Public
Health Tracking Program
NH Department of Health and Human Services,
Division of Public Health Services
29 Hazen Drive  |  Concord, NH 03301
(603) 271-4988  |  (800) 852-3345 ext.4988