Carbon Monoxide:
The Silent Killer

DESCRIPTION:

Carbon monoxide (CO) – sometimes called “the Silent Killer” - is a colorless, odorless, and tasteless gas that is extremely dangerous. It is usually created through the incomplete combustion of carbon-based fuel sources such as gasoline, wood, charcoal, propane or natural gas.

COMFORT AND HEALTH EFFECTS:

The acute effects of exposure to carbon monoxide (CO) are caused by the formation of carboxyhemoglobin in the blood, which inhibit the uptake and transport of oxygen by your circulatory system. In other words, even though you may be breathing normally, your blood is unable to transport oxygen from your lungs to your body's cells where the oxygen is needed. At moderate concentrations, angina (chest pain or a sense of suffocation), impaired vision, and reduced brain function may occur, resulting in headaches, nausea, weakness, dizziness, shortness of breath, confusion and hallucinations. At higher concentrations, CO exposure can be fatal. CO poisoning associated with the use of fuel-burning appliances kills more than 200 people each year in the United States, and sends another 10,000 to hospital emergency rooms for treatment.

SOURCES:

Incomplete combustion in gas ranges and un-vented gas or kerosene heaters may create high concentrations of CO within your home. Poorly maintained combustion devices (such as boilers or furnaces) can be significant sources. Also, the chimney flue may be improperly sized, blocked, disconnected, or may be leaking. Additionally, car, truck, or bus exhaust from attached garages, or nearly roads and parking areas, can also be a source of carbon monoxide.

STANDARDS AND GUIDELINES:

No standards for CO have been agreed upon for indoor air. The U.S. National Ambient Air Quality Standards for Outdoor air are 9 parts-per-million (ppm) or 40 mg/m3 for 8 hours, and 35 ppm for 1 hour.  A level of 1200 ppm is considered to be immediately dangerous to life and health, according to the National Institute for Occupational Safety and Health.

MEASUREMENT METHODS:

A variety of instruments can detect and measure CO in your home. Some relatively high-cost infrared radiation absorption and electrochemical instruments do exist. Moderately priced real-time measuring devices are also available, and are commonly used in homes for protection against CO poisoning. These devices will sound an alarm that is loud enough to warn you if dangerous levels of CO are detected within your home, even if you are sleeping. Passive monitors are available at a much lower price. A passive monitor simply turns color upon the detection of carbon monoxide, but does not sound any audible alarm.

CONTROL MEASURES:

It is very important to keep all combustion equipment maintained and properly adjusted.  People should be certain to have their furnaces checked for safe and proper operation before each heating season.  Vehicular use should be carefully managed adjacent to buildings (in locations such as loading docks or enclosed parking areas) and indoor vocational programs.  Additional ventilation can be used as a temporary measure when high levels of CO are expected for short periods of time.

For more information on Carbon Monoxide or other Indoor Air Quality concerns, contact Scott County Environmental Health by phone (952-496-8652) or by e-mail.