Carbon monoxide is an odorless, colorless gas that interferes with the delivery of oxygen in the blood to the rest of the body. This gas can impede coordination, worsen cardiovascular conditions, and produce fatigue, headache, weakness, confusion, disorientation, nausea, and dizziness. High levels result in death. The symptoms are sometimes confused with the flu or food poisoning. Fetuses, infants, elderly, and people with heart and respiratory illnesses are particularly at high risk for the adverse health effects of carbon monoxide. An estimated 1,000 people die each year as a result of carbon monoxide poisoning and thousands of others end up in hospital emergency rooms. Carbon monoxide is produced by the incomplete combustion of carbon-containing fuels including coal, wood, charcoal, natural gas, and fuel oil. It can be emitted by combustion sources such as unvented kerosene and gas space heaters, furnaces, wood stoves, gas stoves, fireplaces and water heaters, automobile exhaust from attached garages, and tobacco smoke. Problems can arise as a result of improper installation, maintenance, or inadequate ventilation.

Chimneys blocked by birds’ or squirrels’ nests can cause deadly carbon monoxide gas to enter a home. This danger can be lessened by having the chimney professionally cleaned each year. A carbon-monoxide alarm will provide added protection, but such alarms are not a replacement for proper use and maintenance of fuel-burning appliances. Proper placement of a carbon monoxide detector is important. Because victims of carbon monoxide poisoning will slip deeper into unconsciousness as their condition worsens, a loud alarm is necessary to wake them. Additional detectors on every level and in every bedroom of a home provide extra protection. Homeowners should not install carbon monoxide detectors directly above or beside fuel-burning appliances, as appliances may emit a small amount of carbon monoxide upon start-up. A detector should not be placed within fifteen feet of heating or cooking appliances or in or near very humid areas such as bathrooms. Carbon monoxide rises with warmer air temperatures and so mounting the device on or near the ceiling is often recommended.