What is carbon monoxide?
Carbon monoxide (CO) is odorless, colorless, and tasteless. When it is breathed into your body, it
combines with your blood and prevents it from absorbing oxygen. It's responsible for half of the fatal
poisonings in the U.S. each year.

Where does it come from?
Carbon monoxide is produced by incomplete combustion of fuels such as oil, propane, coal, wood,
natural gas, gasoline, diesel fuel, charcoal, and kerosene. Faulty or inadequately vented vehicles and
appliances that use these fuels -- furnaces, fireplaces, wood stoves, charcoal grills, kerosene heaters,
gasoline-powered vehicles, lawn mowers, and snow blowers -- can produce deadly amounts of
carbon monoxide.

What are the medical effects of carbon monoxide and how do I recognize them?
Carbon monoxide (CO) inhibits the blood's ability to carry oxygen to body tissues including vital
organs such as the heart and brain. When CO is inhaled, it combines with the oxygen carrying
hemoglobin of the blood to form carboxyhemoglobin (COHb). Once COHb is formed, that
hemoglobin is no longer available for transporting oxygen. How quickly the carboxyhemoglobin
builds up is a factor of the concentration of the gas being inhaled, as measured in parts per million
(PPM), and the duration of the exposure. Compounding the effects of the exposure is the long
half-life of carboxyhemoglobin in the blood. Half-life is a measure of how quickly levels return to
normal. The half-life of carboxyhemoglobin is approximately 5 hours. This means that for a given
exposure level, it will take about 5 hours for the level of carboxyhemoglobin in the blood to drop to
half its current level after the exposure is terminated.

The following table describes the symptoms associated with a given concentration of COHb:

COHb     Symptoms and Medical Consequences

10%      No symptoms. (Heavy smokers can have as much as 9% COHb.)

15%      Mild headache.

25%      Nausea and serious headache.  Fairly quick recovery after

         treatment with oxygen and/or fresh air.

30%      Symptoms intensify.  Potential for long term effects especially

         in the case of infants, children, the elderly, victims of

         heart disease and pregnant women.

45%      Unconsciousness.

50%+     Death.

Since one can't easily measure COHb levels outside of a medical environment, CO toxicity levels are
usually expressed in airborne concentration levels of parts per million (PPM) and duration of
exposure. Expressed in this way, symptoms of exposure can be stated as follows:

    PPM CO      Time        Symptoms

    35 PPM      8 hours     Maximum exposure allowed by OSHA in the workplace over an eight hour period.

   200 PPM    2-3 hours     Mild headache, fatigue, nausea and dizziness.

   400 PPM    1-2 hours     Serious headache, other symptoms intensify.

                            This level is life threatening after 3 hours.

   800 PPM    45 minutes    Dizziness, nausea and convulsions.

                            Unconscious within 2 hours.

                            Continued exposure: Death within 2-3 hours.

  1600 PPM    20 minutes    Headache, dizziness and nausea.

                            Continued exposure: Death within 1 hour.

  3200 PPM   5-10 minutes   Headache, dizziness and nausea.

                            Continued exposure: Death within 1 hour.

  6400 PPM   1-2 minutes    Headache, dizziness and nausea.

                            Continued exposure: Death within 25-30 minutes.

12,800 PPM   1-3 minutes    Death.

As can be seen from the information above, the symptoms vary widely based on exposure level,
duration and the general health and age on an individual. Also note the one recurrent theme that is
most significant in the recognition of carbon monoxide poisoning is headache, dizziness and
nausea. These "flu like" symptoms are often mistaken for a real case of the flu and can result in
delayed or misdiagnosed treatment. When experienced in conjunction with the sounding of a carbon
monoxide detector these symptoms are the best indicator that a potentially serious buildup of carbon
monoxide exists.

Symptoms and Signs
Carbon Monoxide is especially dangerous for children, older adults and people who have heart or
respiratory conditions. It can cause headaches, nausea, fatigue, dizziness, drowsiness, and burning
eyes. Prolonged exposure causes more severe symptoms, including confusion, disorientation,
convulsions, and unconsciousness. In very severe cases, carbon monoxide poisoning can be fatal.

If anyone is experiencing these symptoms, get immediate medical help. Call 911 and get outside to fresh air.

Here are some other warning signs:

     Stale or stuffy air
     Excessive moisture on windows and walls
     Soot buildup around appliance vents
     Abnormal gas flame at appliance

What can I do to prevent carbon monoxide poisoning?
The New Market Volunteer Fire Department recommends annual inspections for furnaces, water heaters, and equipment, including venting and chimneys. Here are some additional steps you can take to reduce the chance that carbon monoxide might build to harmful levels:

     Purchase and install one or more Carbon Monoxide Detectors in your home
     Regularly check the flame on natural gas appliances. It should be blue. If it's yellow, its a sign
     that the fuel isn't burning completely and could produce carbon monoxide. Turn the appliance
     off and call us or your appliance repair service.
     Keep flues and chimneys clean and free of debris. To test for blocked chimneys or vents
     leading from your furnace, turn on your furnace for 10 minutes and turn it off. Hold your hand
     under the vent hood (CAUTION: DO NOT TOUCH). If hot air comes out, call us or your
     furnace service for an inspection.
     Repair rusted or pitted flue pipes leading from your furnace and water heater to the chimney.
     Do not block the furnace air intake. If your furnace is housed in a small room, provide
     adequate fresh air through louvered doors or other fresh-air grills.
     Never use a gas range or unvented space heater to heat your home.
     Keep your garage door open whenever a vehicle inside it is idling.
     Start lawn mowers and snow blowers outside, rather than inside the garage.
     Never use a barbecue grill inside your home, an enclosed porch, or your garage.

If your carbon monoxide detector sounds an alarm, do not panic. Follow these simple steps:

     Check to see if anyone is experiencing these symptoms: nausea, burning eyes,
     light-headedness or dizziness, unconsciousness. If you notice these symptoms, get
     immediate medical help. Call 911,and get outside to fresh air immediately.
     If there is no emergency, evaluate the situation.
     Open doors and windows to vent your home.
     Turn furnace thermostat to its lowest setting.
     Turn off all unvented appliances (range, auxiliary heater).
     Turn gas or oil water heater to its lowest setting.
     Check flues for obstructions.
     Check for soot at the base of the water heater and furnace.
     Check for vehicle or small engine operating in attached garage or basement.
     Check the detector and other conditions: Is it located near the kitchen, bathroom, or other
     areas where unvented appliances, chemicals, or humidity can cause the alarm to sound? Is it
     located near where people were smoking? Were cleaning products recently used nearby? Did
     the alarm sound when the weather included prolonged rain or dense fog?
     If you can't find a problem and no one is ill, call a carbon monoxide professional to help you
     evaluate your situation.