What Is Carbon Monoxide Poisoning?

Carbon monoxide (or CO) is an odorless, tasteless, invisible gas that is sometimes called the silent killer because it poisons and kills many people each year, without them ever being aware of the danger. Here's a look at how carbon monoxide can kill you, the risk factors, and how to detect carbon monoxide and prevent injury or death.

Carbon monoxide cannot be heard, smelled, or tasted, but it's produced by virtually every item in your home or garage that burns fuel. Particularly dangerous are automobile fumes in an enclosed garage or a closed car. By the time you're aware that something is wrong, there's a good chance you won't be able to function well enough to open a window or leave the building or car.

When you breathe in carbon monoxide, it enters your lungs and binds to the hemoglobin in your red blood cells. The problem is that hemoglobin binds to carbon monoxide over oxygen, so as the level of carbon monoxide increases, the amount of oxygen your blood carries to your cells decreases. This leads to oxygen starvation or hypoxia.

At low concentrations, the symptoms of carbon monoxide poisoning resemble the flu: including headaches, nausea, and fatigue. Continued exposure or higher concentrations can lead to confusion, dizziness, weakness, drowsiness, severe headache, and fainting. If the brain doesn't get enough oxygen, carbon monoxide exposure can lead to unconsciousness, coma, permanent brain damage, and death.

The effects can become deadly within minutes, but long-term low-level exposure is not uncommon and leads to organ damage, disease, and a slower death.

Infants, children, and pets are more susceptible to the effects of carbon monoxide than adults, so they are at greater risk for poisoning and death. Long-term exposure can lead to neurological and circulatory system damage, even when the levels aren't high enough to produce a significant effect in adults.

Carbon monoxide naturally occurs in air, however dangerous levels are produced by any type of incomplete combustion. Examples are common in the home and workplace:

• Incomplete burning of any fuel, such as propane, gasoline, kerosene, natural gas
• Automobile exhaust fumes
• Tobacco smoke
• Blocked or faulty chimneys
• Burning any fuel in an enclosed space
• Improperly functioning gas appliances
• Wood-burning stoves

The best protection against carbon monoxide poisoning is a carbon monoxide alarm, which alerts you whenever carbon monoxide become elevated. There are detectors designed to sound before CO levels become dangerous and there are detectors that tell you how much carbon monoxide is present. The detector and alarms should be placed anywhere there is a risk of carbon monoxide build-up, including rooms with gas appliances, fireplaces, and garages.

You can reduce the risk of carbon monoxide building to critical levels by cracking a window in a room with a gas appliance or fire, so fresh air can circulate.