Carbon Monoxide (CO)*

Sources: Unvented kerosene and gas space heaters; leaking chimneys and furnaces; back-drafting from furnaces, gas water heaters, woodstoves, and fireplaces; gas stoves. Automobile exhaust from attached garages. Environmental Tobacco Smoke.

Health Effects: At low concentrations, fatigue in healthy people and chest pain in people with heart disease. At higher concentrations, impaired vision and coordination; headaches; dizziness; confusion; nausea. Can cause flu-like symptoms that clear up after leaving home. Fatal at very high concentrations.

Levels in Homes: Average levels in homes without gas stoves vary from 0.5 to 5 parts per million (ppm). Levels near properly adjusted gas stoves are often 5 to 15 ppm and those near poorly adjusted stoves may be 30 ppm or higher.

Steps to Reduce Exposure:

• Keep gas appliances properly adjusted.
  
  
• Consider purchasing a vented space heater when replacing an unvented one.
  
  
• Use proper fuel in kerosene space heaters.
  
  
• Install and use an exhaust fan vented to outdoors over gas stoves.
  
  
• Open flues when fireplaces are in use.
  
  
• Choose properly sized woodstoves that are certified to meet EPA emission standards.
  
  
• Make certain that doors on all woodstoves fit tightly.
  
  
• Have a trained professional inspect, clean, and tune-up central heating system (furnaces, flues, and chimneys) annually. Repair any leaks promptly.
  
  
• Do not idle the car inside garage.
  
  

* From www.epa.gov