Carbon Monoxide

Learn the facts about carbon monoxide.

Under normal operating conditions, natural gas burns cleanly, producing heat, carbon dioxide and water vapor. Natural gas is non-toxic and is the cleanest burning fossil fuel available. But if natural gas isn’t burning properly or the appliance has a mechanical problem, it could create a hazard.

Incomplete combustion of natural gas produces carbon monoxide (CO), which is an odorless, poisonous and potentially fatal gas. Some indicators of incomplete combustion are a yellow flame (blue is normal) or combustion odors and soot around the front of the furnace or water heater.

If you or other members of the household feel out of breath, dizzy, nauseous and have headaches, you could be suffering from carbon monoxide poisoning—leave your home, then call 911.

How to Prevent CO Poisoning

The best way to prevent CO poisoning is to have your gas appliances inspected regularly by a qualified technician or by NW Natural’s service personnel:

  • Make sure that all vents and chimneys are properly installed and inspected regularly for improper connections, visible rust or stains.
  • Keep chimneys and vents free of debris, such as leaves, creosote and animal nests.
  • Make sure heating equipment and appliances are installed correctly and maintained regularly. NW Natural offers free annual equipment inspections as part of our standard service to customers.
  • Installing and properly maintaining a UL-approved carbon monoxide detector can alert you when a certain level of CO is in the air, but should not replace regular maintenance on appliances. Follow the manufacturer's instructions for installation. Contact your state fire marshal’s office for information regarding proper placement, testing and maintenance of carbon monoxide detectors.
  • Look out for problems that could signal improper appliance operation, such as:
    • Burning or unfamiliar odors
    • Furnace constantly running or unable to heat the house
    • Moisture inside of windows
    • Soot

Protect Yourself

Take the following precautions to further prevent CO poisoning:

  • Never burn a charcoal or wood grill indoors or in a garage.
  • Never sit in a parked car with the engine running and the windows closed.*
  • Never operate a car in an enclosed area, such as a garage.*
  • Never operate kerosene or propane heaters indoors without proper venting.
  • Never use the gas range or oven for home heating.

* Vehicle exhaust is responsible for more than half of the unintentional CO deaths each year.