Hazard Alert: Carbon Monoxide

What is carbon monoxide?

Carbon monoxide (CO) is a potentially deadly gas. It is colorless, odorless, tasteless and non-irritating. It is generally produced as a by-product from the incomplete burning of carbon-containing fuels such as wood, oil, natural gas, kerosene, coal and gasoline. The normal background level of CO in a home varies depending on cigarette smoking, heating and cooking but is generally a few parts per million (ppm). The World Health Organization recommends that indoor air levels for CO be kept below an average of nine ppm for any eight-hour period, and below 35 ppm for any one-hour period.

What are the sources of carbon monoxide?

Potential sources for CO in the home include a leaking or clogged chimney pipe or flue, cracked heat exchanger, gas- or wood-burning fireplace, and any of the following non-electric appliances: corroded or disconnected water heater vent pipe, unvented clothes dryer, improperly installed kitchen range or cooktop vent, or portable space heaters. Schedule annual maintenance on all furnaces and other heat sources to ensure they are properly vented and maintained. Operating a barbecue grill indoors, using a gas kitchen range to provide heat, or letting an automobile run in a closed garage also increases carbon monoxide levels indoors.

Another potential source of carbon monoxide gas is a blocked exhaust pipe in a running car or truck. A car's exhaust pipe may be buried in ice or snow by a very heavy snowfall or by a passing snowplow. The exhaust pipe can also become blocked after backing into a snowbank. Carbon monoxide exhaust can seep into the vehicle's interior through leaks or cracks in the floorboard. Check your vehicle's exhaust pipe to be sure it is not blocked by snow.

Portable generators can also be a source of CO poisoning. While portable generators are useful for providing electricity, such as during a power outage, they release much higher levels of CO than the amount of CO emitted by an idling car. When operating a portable generator, place it outside and away from windows and doors. Never use a portable generator in the home or basement, even if windows are open, and never operate the generator inside an enclosed structure, such as a garage or porch.

What are the symptoms of carbon monoxide poisoning?

When CO is breathed in, it attaches to the hemoglobin in the bloodstream and prevents the body from getting the oxygen it needs. As exposure to CO continues, the level of carboxyhemoglobin in the blood (the amount of carbon monoxide attached to hemoglobin) increases and less hemoglobin is available to carry oxygen through the body. This lack of oxygen results in the symptoms associated with CO poisoning. Initial symptoms of CO poisoning can be mistaken for flu symptoms. Depending on how long and to how much CO you have been exposed, you can experience any of the following symptoms: headaches, dizziness, weakness, nausea, loss of muscle control, shortness of breath, chest tightness, visual changes, sleepiness, fluttering of the heart, redness of the skin, and confusion and mild behavioral effects such as slowed reaction time and altered driving skills. CO poisoning should be suspected if more than one member of the family is sick and if they feel better after being away from home for a period of time. At high levels, or continued exposure, CO can cause suffocation, resulting in loss of consciousness, brain damage, or death.

Are some people more sensitive to the effects of CO exposure?

Age and general health may affect susceptibility to CO. Even low levels of CO can present a health risk to sensitive populations such as the elderly, infants, the unborn, and those with heart or breathing problems.

What should I do if I suspect carbon monoxide poisoning?

Immediately leave your home and contact the fire department, and the gas company or heating contractor. Remember that you cannot smell CO and, as symptoms of CO poisoning increase, you may become confused and less capable of making decisions that could save your life.

What about carbon monoxide detectors?

Portable CO detectors are available for purchase. They are similar to smoke detectors and are designed to sound a warning before CO levels in the blood become elevated and cause death. The detectors should provide adequate warning as CO levels in the air increase gradually over a period of an hour or more. These are the conditions that typically occur due to a faulty furnace or stove.

Select a CO detector which is battery-powered or has a battery back-up and is certified by Underwriters Laboratories (UL). CO detectors should be placed according to manufacturer installation instructions. Check the CO detector batteries twice each year and replace them, if necessary. Read the CO detector owner's manual to learn about the warning sounds and how to test the device. A CO detector is not a substitute for regular maintenance of CO sources. For further assistance, please check with your local fire department.