Carbon Monoxide Safety

Although the popularity of carbon monoxide (CO) alarms has been growing in recent years, it cannot be assumed that everyone is familiar with the hazards of carbon monoxide poisoning in the home.

Often called the silent killer, carbon monoxide is an invisible, odorless, colorless gas created when fuels (such as gasoline, wood, coal, natural gas, propane, oil, and methane) burn incompletely. In the home, heating and cooking equipment that burn fuel are potential sources of carbon monoxide. Vehicles or generators running in an attached garage can also produce dangerous levels of carbon monoxide.

Symptoms of CO Poisoning



CO enters the body through breathing. CO poisoning can be confused with flu symptoms, food poisoning and other illnesses. Some symptoms include shortness of breath, nausea, dizziness, light headedness or headaches. High levels of CO can be fatal, causing death within minutes.

The concentration of CO, measured in parts per million (ppm) is a determining factor in the symptoms for an average, healthy adult.

  • 50 ppm: No adverse effects with 8 hours of exposure.
  • 200 ppm: Mild headache after 2-3 hours of exposure.
  • 400 ppm: Headache and nausea after 1-2 hours of exposure.
  • 800 ppm: Headache, nausea, and dizziness after 45 minutes; collapse and unconsciousness after 1 hour of exposure.
  • 1,000 ppm: Loss of consciousness after 1 hour of exposure.
  • 1,600 ppm: Headache, nausea, and dizziness after 20 minutes of exposure.
  • 3,200 ppm: Headache, nausea, and dizziness after 5-10 minutes; collapse and unconsciousness after 30 minutes of exposure.
  • 6,400 ppm: Headache and dizziness after 1-2 minutes; unconsciousness and danger of death after 10-15 minutes of exposure.
  • 12,800 ppm: Immediate physiological effects, unconsciousness and danger of death after 1-3 minutes of exposure.

Facts & Figures



  • According to the Consumer Product Safety Commission, an average of 166 people die each year are due to carbon monoxide poisoning .
  • The dangers of CO exposure depend on a number of variables, including the victim's health and activity level. Infants, pregnant women, and people with physical conditions that limit their body's ability to use oxygen (i.e. emphysema, asthma, heart disease) can be more severely affected by lower concentrations of CO than healthy adults would be.
  • A person can be poisoned by a small amount of CO over a longer period of time or by a large amount of CO over a shorter amount of time.
Source: NFPA's Fire Protection Handbook, 19th Edition

Related Information
View a Carbon Monoxide Fact Sheet (PDF)