Learn about the causes of carbon monoxide and what you can do to prevent carbon monoxide poisoning.

What is Carbon Monoxide?

Carbon monoxide (CO) is a dangerous gas that you cannot smell, taste or see. It is produced when carbon-based fuels, such as kerosene, gasoline, natural gas, propane, charcoal or wood are burned without enough oxygen, causing incomplete combustion.

What Causes Carbon Monoxide?

In the case of natural gas appliances, this can be caused by improper installation, poor maintenance, appliance misuse or failure.

Carbon Monoxide Poisoning

Carbon monoxide can build up in a home or other structure when gas appliances are not working properly or when combustion gases are not being safely vented to the outside. Breathing in carbon monoxide can displace the oxygen in your blood, causing carbon monoxide poisoning. Severe cases of carbon monoxide poisoning can be deadly.

Symptoms of Carbon Monoxide Poisoning

The stages of carbon monoxide poisoning produce unexplained symptoms, such as:

  • Sudden flu-like symptoms
  • Headaches, shortness of breath, fatigue
  • Nausea or vomiting
  • Dizziness, lightheadedness, mental confusion, drowsiness
  • Rapid or fluttering heartbeat
  • Unconsciousness

Signs of Carbon Monoxide

Here are some of the most common signs of carbon monoxide:

  • A yellow, large and unsteady natural gas appliance burner flame (with the exception of decorative natural gas log appliances).
  • An unusual pungent odor when the appliance is operating. This may indicate the creation of aldehydes, a by-product of incomplete combustion.
  • Unexplained nausea, drowsiness and flu-like symptoms.

What to Do if You Suspect Carbon Monoxide

If you think that carbon monoxide may be present in your home or office:

  • If it's safe to do so, immediately turn off the suspected gas appliance and windows to ventilate the area.
  • Evacuate the building and do not let anyone back in until safe to do so.
  • Call 911 and seek immediate medical attention if anyone experiences any symptoms of carbon monoxide poisoning.
  • Contact us at 1-800-427-2200 or a qualified professional immediately to have the appliance inspected.
  • Don't use the suspected appliance until it's been inspected, serviced and determined to be safe.

How to Prevent Carbon Monoxide

To keep your natural gas appliances operating safely and efficiently, make sure to have them checked every year (either by SoCalGas or a licensed, qualified professional). Not performing yearly maintenance may result in inefficient appliance operation, and in some cases, dangerous exposure to carbon monoxide.

Here are some additional tips for preventing carbon monoxide:

  • Vacuum around burner compartments, and inspect and replace furnace filters on forced-air units or central heating systems according to manufacturer instructions.
  • Make sure to properly replace the front panels of a forced-air unit or the burner compartment door of a natural gas wall heater.
  • Never store anything near a natural gas appliance that might interfere with normal appliance airflow.
  • Make sure that appliance venting is intact and unblocked. Have all natural gas appliances and venting repairs done by a qualified professional.
  • In higher altitude areas, where snow can accumulate on rooftops, make sure that natural gas appliance intake and exhaust vents are clear of obstructions.
  • When using your natural gas fireplace, make sure the damper is open. Never use your natural gas oven for space heating.
  • Natural gas appliance maintenance is always the homeowner’s responsibility. However, we'll be happy to perform appliance safety checks upon request.

Carbon Monoxide Alarms

California's Carbon Monoxide Poisoning Prevention Act of 2010 requires that all residential properties with a fossil fuel burning appliance, fireplace or attached garage be equipped with an approved carbon monoxide alarm for each sleeping area and on every level of the home.

Even though carbon monoxide alarms may provide an extra level of safety, they require routine maintenance and replacement at least every three to five years to perform properly. Even with alarms in place, regular natural gas appliance maintenance is still required. Inspection and routine maintenance are still an effective defense against accidental carbon monoxide poisoning from natural gas appliances.