Ashley Clay, MSPAS
PA-C Medcor Provider

What is a deadly gas emitted from burning fuel that is colorless, odorless, tasteless, and referred to as the “silent killer” or the “invisible killer”?  Carbon monoxide. Each year more than 400 Americans die from unintentional carbon monoxide poisoning.

Carbon monoxide (CO) is a tasteless, odorless gas that is found in certain types of carbon-containing fuels, like gasoline, wood, propane, or charcoal. Carbon monoxide poisoning can occur when the gas builds up in the air around you and is breathed in. begins to replace oxygen in the bloodstream, which carries the poisonous gas throughout the body.  

Without immediate fresh air and treatment, a person breathing in CO can lose consciousness, have a seizure, slip into a coma, and potentially die. Death may result after only a few minutes of exposure to higher concentrations of CO.

How do dangerous levels of carbon monoxide get in the air?

Carbon monoxide is released into the air when you burn fuel such as gasoline, wood, propane, or charcoal. Levels can build up in your home and workplace, especially in areas that are enclosed or improperly ventilated. These fumes are released by common sources including cars or trucks, small engines like lawnmowers, furnaces, grills, stoves, lanterns, fireplaces, gas ranges, gas generators, and space heaters.

People who work around motor vehicles, coke ovens, blast furnaces, boiler rooms, garages, docks, warehouses or have occupations in petroleum refining, steel production, or pulp and paper production are more likely to be exposed to CO.

What are symptoms of CO poisoning?

Exposure to carbon monoxide can lead to symptoms of:

  • A general feeling of being ill
  • Headache
  • Dizziness
  • Weakness
  • Shortness of breath
  • Blurred vision
  • Nausea and/or vomiting
  • Chest pain
  • Confusion
  • Drowsiness or loss of consciousness

Elderly individuals, those who are sleeping or intoxicated, and infants may not recognize the early signs of CO poisoning and can die before they realize there is a problem. More than one-third of deaths occur when the victim is asleep. The CDC cautions that in addition to elderly and infants, individuals with chronic heart disease, anemia, or breathing problems are at an increased risk of illness and/or death from CO exposure. Unborn babies are also at high risk of death from CO exposure.

Seek immediate medical attention and get fresh air if you or someone you are with may be suffering from CO poisoning.

How do I prevent CO poisoning?

The CDC outlines strategies to prevent CO poisoning at home, including:

  • Install carbon monoxide detectors in your home. These are different than smoke detectors. Place them outside common areas, outside of each bedroom, in the garage, and on every level of the home. Also install them on boats and inside campers. Test smoke and CO alarms once a month. Check the batteries twice each year (do not forget to check your smoke detectors, too!). A good rule of thumb, when the time changes (“spring forward” or “fall back”) remember to check/change the batteries. Check that the CO detectors have a battery backup. Replace CO detectors every 5 years.
  • Be aware of the hazards of burning fuel in your home. Do not use outdoor grills or portable chemical heaters indoors. Never grill in the garage. Never use a gas range or oven to heat your home. Never use portable gas camp stoves inside. Never use a generator inside your home or garage.
  • Have qualified technicians service your appliances each year, including furnaces, water heaters, and any appliance that burns gas, oil, or coal. Make sure all appliances are properly vented to the outside.
  • Have your chimney inspected every year. If your chimney is clogged, CO won’t be vented out and can build up inside.
  • Vehicle safety is important. NEVER run your car inside your garage if it’s attached to your house (even if the garage door is open!). Have mechanic check the exhaust system of your vehicles for leaks each year.

For additional information, visit the United States Consumer Product Safety Commission’s Carbon Monoxide Information Center.

The Occupational Safety and Health Administration’s recommendations to prevent CO poisoning in the workplace include:

  • Educate workers on CO poisoning as well as conditions that can bring about exposures to carbon monoxide.
  • Install an effective ventilation system.
  • Install carbon monoxide detectors everywhere CO poisoning could be a risk.
  • Don’t use fuel-burning equipment in enclosed, partially enclosed, or poorly ventilated spaces.
  • Maintain CO-producing equipment and appliances. OSHA encourages using equipment powered by electricity, batteries, or compressed air when safe to do so instead of gas-powered equipment.
  • Provide personal CO monitors with alarms where there is potential exposure to CO.
  • Use appropriate certified respirators in atmospheres where there are known levels of CO.
  • Report any situation that could cause a buildup of CO to supervisors.
  • Immediately report any symptoms like dizziness, drowsiness, or nausea that could be CO poisoning.

For details on OSHA’s recommended actions to prevent CO poisoning, read OSHA’s Carbon Monoxide Fact Sheet.

This article is not intended to diagnose or treat any condition or to give medical advice. Always consult your primary care provider for healthcare instructions. External links are provided as references and do not indicate an endorsement by Medcor. External links are subject to other sites’ terms of use and privacy policies.


Centers for Disease Control and Prevention, “Carbon Monoxide Poisoning Frequently Asked Questions,”

Mayo Clinic, “Carbon Monoxide poisoning,”

Harvard Health Publishing, “Carbon Monoxide Poisoning,”

Occupational Safety and Health Administration, “OSHA reminds employers to protect workers from dangers of carbon monoxide exposure,”

Occupational Safety and Health Administration, “Carbon Monoxide Poisoning,”