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Understanding Carbon Monoxide Levels and Their Impact on Health

June 18, 2026 · The Clime Team
Understanding Carbon Monoxide Levels and Their Impact on Health

Carbon monoxide (CO) is a colorless, odorless gas produced by the incomplete combustion of fuels such as natural gas, coal, wood, gasoline, and others. It's commonly emitted by appliances like gas stoves, furnaces, and fireplaces, as well as vehicles and generators. Due to its undetectable nature, CO poses significant health risks, making it crucial to understand its levels and take preventive measures.

What Are Typical Carbon Monoxide Levels?

In residential settings, CO concentrations vary based on the presence and condition of fuel-burning appliances:

  • Homes without gas stoves: Average levels range from 0.5 to 5 parts per million (ppm).

  • Homes with properly adjusted gas stoves: Levels are typically between 5 to 15 ppm.

  • Homes with poorly adjusted gas stoves: Levels can rise to 30 ppm or higher. (epa.gov)

It's important to note that prolonged exposure to CO levels between 1 to 70 ppm usually doesn't cause symptoms in healthy individuals. However, higher concentrations can lead to health issues. (cpsc.gov)

What Are the Health Effects of Carbon Monoxide Exposure?

CO exposure can lead to a range of symptoms, depending on the concentration and duration:

  • Low to moderate exposure (1 to 70 ppm): Symptoms may include headache, fatigue, shortness of breath, nausea, and dizziness.

  • High exposure (above 70 ppm): Symptoms can escalate to mental confusion, vomiting, loss of muscular coordination, loss of consciousness, and potentially death. (cpsc.gov)

What Are the National Standards for Carbon Monoxide Levels?

The U.S. Environmental Protection Agency (EPA) has established standards to protect public health:

  • 8-hour average: 9 ppm, not to be exceeded more than once per year.

  • 1-hour average: 35 ppm, not to be exceeded more than once per year. (law.cornell.edu)

How Can I Protect Myself and My Family from Carbon Monoxide?

To minimize the risk of CO exposure:

  • Maintain and properly adjust combustion appliances: Regular maintenance ensures efficient operation and reduces CO production. (epa.gov)

  • Install CO detectors: Place alarms near sleeping areas to alert you of elevated CO levels. (epa.gov)

  • Ensure proper ventilation: Use exhaust fans over gas stoves and open flues when fireplaces are in use. (epa.gov)

  • Avoid idling vehicles in enclosed spaces: Never leave cars running in garages or other confined areas. (cpsc.gov)

By understanding CO levels and implementing these safety measures, you can significantly reduce the risk of carbon monoxide poisoning in your home.

Highlights:

  • Carbon Monoxide Trends | US EPA, Published on Wednesday, February 18
  • Carbon Monoxide NAAQS Review - Analyses and Data Sets | US EPA, Published on Wednesday, February 18

Frequently Asked Questions