How to recognize and prevent CO poisoning

Carbon monoxide (CO) is a gas that can build up to dangerous levels indoors when fuel-burning devices are not properly operated, vented or maintained. Because it has no odor, color or taste, CO cannot be detected by smell, taste or sight.

The U.S. Consumer Product Safety Commission estimates CO poisoning due to residential fuel-burning devices kills about 200 to 250 people every year in the United States. In addition, the commission estimates that 8,000 to 15,000 people each year are examined or treated in hospitals for non-fire-related CO poisoning.

Breathed over long periods of time, low levels of CO may cause other illness. Fortunately, simple preventive measures can prevent CO problems, and a CO alarm can detect potentially deadly conditions.

What are the sources of CO? In general, CO is produced whenever any fuel — gas, oil, kerosene, wood or charcoal — is burned. However, more is produced when there isn't enough oxygen for efficient burning. Common sources of CO in homes include furnaces, gas space heaters, gas stoves, water heaters, fireplaces, charcoal grills, wood stoves, lawn mowers, power generators, camp stoves, motor vehicles and some power tools with internal combustion engines. Smoking is another common source of CO that impacts indoor air quality.

What are the symptoms of CO poisoning? The health effects of breathing CO depend on the level of CO in the air, the duration of exposure and the health status of the exposed person. For example, fetuses, infants, the elderly and people with anemia or with a history of heart or respiratory disease can be especially susceptible.

At higher levels, people who breathe CO typically feel flu-like symptoms, including nausea, tiredness, headaches, dizziness, which may progress to confusion, and impaired vision and coordination.

After breathing higher levels of CO for a long time, a person may lose consciousness, slip into a coma and die. CO is called the "silent killer" because if the early signs are ignored, a person may lose consciousness and be unable to escape the danger.

So how can you tell the difference between CO poisoning and the flu? It could be CO poisoning if:

• You feel better when you are away from your home.

• Several people in the home gets sick at the same time (the flu is usually passed from person to person).

• The family members who are most affected spend the most time in the home.

• Symptoms occur or get worse shortly after turning on a fuel-burning device (furnace, oven, fireplace) or running a vehicle in attached garage.