Carbon Monoxide: The Silent Killer

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Carbon monoxide
Poison Safety & Prevention

Each year in the United States, more than 200 accidental deaths are caused by carbon monoxide (CO) poisoning. It is considered the leading cause of death from poisoning in the United States. The Texas Poison Center Network documents hundreds of carbon monoxide poisonings each year.

The Silent Killer 

Commonly known as the “silent killer”, its presence is not known until symptoms of the exposure are experienced. It is a colorless, odorless, tasteless, and potentially dangerous gas. You can’t see it or smell it. It is a by-product from the incomplete burning of carbon-containing fuels such as coal, gasoline, kerosene, natural gas, oil and wood. Even without a sustained cold spell, residents need to be aware of a silent killer. Mal-functioning gas, oil and kerosene heaters can release carbon monoxide (CO) gas into the surrounding air and present a serious health threat to family members. Mal-functioning automobiles also pose a risk.

When the gas is inhaled, it reduces the amount of oxygen the blood can carry to the vital organs, in particular, the heart and the brain. Continued mild exposure may result in serious long-term effects. However, since the gas cannot be detected without special testing equipment, it usually goes unnoticed, resulting in the majority of people being killed while sleeping.


Anyone can become a victim of carbon monoxide; it does not discriminate.


Many people mistake their symptoms for the beginning signs of the flu or a cold. It typically affects the entire family (and often pets) simultaneously. 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, carbon monoxide poisoning should be suspected. The very young and very old are the most vulnerable to the effects of CO. Below are lists of early and severe symptoms of carbon monoxide poisoning.

Early Symptoms

  • Headache, throbbing
  • Dizziness
  • Weakness
  • Nausea and vomiting
  • Fast pulse
  • Visual changes

Severe Symptoms

  • Fainting
  • Confused
  • Irregular heartbeat
  • Coma
  • Seizures
  • Stop breathing
  • Heart attack


The treatment of CO poisoning is fresh air and oxygen.

Safety Tips

Several measures can to taken to prevent an exposure to carbon monoxide in the home.

  1. Before turning on your heating system each winter, have it inspected by a qualified contractor.
  2. Clean your chimney and flue, ensuring that it is clear of leaves, branches, birds’ nests or other obstruction.
  3. Gas, oil, or kerosene type space heaters should be cleaned and serviced yearly. When using these heaters, follow the manufacturer’s instructions and allow for good ventilation.
  4. Do not use appliances and equipment such as ovens and grills that are not designed as heat sources.
  5. Don’t forget there are other sources of carbon monoxide such as automobile exhaust systems. Do not leave a car motor running in a closed garage. It could produce enough carbon monoxide to harm people in the garage and in the rooms above or adjacent to the garage.
  6. Gas ranges should never be used for heating, even during power failures. This lowers the amount of oxygen in the kitchen raising the carbon monoxide level. All gas flames in your kitchen range should be blue in color. A yellow flame or a flame that is excessively high, noisy and sputtering indicates improper combustion.
  7. Do not burn coal or charcoal in a closed space. It should never be used indoors, in a fireplace, or the garage.
  8. Install a carbon monoxide detector in your house. A carbon monoxide detector will alert you to CO in the house. Install at least one detector near the sleeping area. Detectors should be placed at least 15 feet from the furnace. If a home has multiple floors, a detector on every level provides extra protection. Detectors are essential in homes with fuel source heat including space heaters, wood burning stoves and fireplaces. It is recommended that you choose a detector listed by Underwriters Laboratories Inc. that sounds an audible alarm.

Suspected CO Poisoning

The Texas Poison Center Network Educators, remind “the best ways to prevent an exposure to CO is to regularly maintain your heating system and install a detector.” When the temperature drops, the welcomed warmth from many heat sources comes with the unwelcome presence of carbon monoxide. Anyone suspecting carbon monoxide poisoning should get to fresh air immediately, and then call their local Poison Center at 1-800-222-1222.