Carbon monoxide: Know the warning signs and steps to take

Even though you can’t see, taste or smell carbon monoxide, there are some telltale warning signs. Here’s how you can protect yourself against this harmful gas, which can poison the air you breathe.

Look for warning signs and symptoms

Carbon monoxide (CO) is formed when carbon-based fuels – such as gasoline, propane, natural gas, oil or wood – don’t burn completely (incomplete combustion). When you’re using an appliance that runs on natural gas, pay attention to the following warning signs:

  • A yellow, large and unsteady burner flame (except in natural gas fireplace logs).
  • Built-up soot in the appliance.
  • An unusual, pungent odor that can indicate the presence of another byproduct of incomplete combustion.
  • Triggering of a carbon monoxide detector or alarm.
  • Household members with unexplained nausea, drowsiness, mental confusion or flu-like symptoms, such as headaches, dizziness, vomiting or shortness of breath.

Act immediately

Take the following steps right away if you think you’ve been exposed to carbon monoxide:

  • Immediately turn off the suspected gas appliance, if it’s safe to do so.
  • Get everyone out of the house and call 911.
  • Seek medical attention for anyone who feels ill.
  • Arrange an inspection immediately and don’t use the appliance until a qualified, licensed professional confirms it’s safe. We can perform this inspection if you’re an SDG&E gas customer; call 1-800-411-7343.

Prevention is your best defense

To help prevent carbon monoxide from being produced in the first place, keep your natural gas appliances in good working order. Schedule an annual safety checkup with us or a qualified, licensed professional.

Also check your carbon monoxide detector or alarm at least once a year to make sure it works properly. Replace the device itself every three to five years, as needed.

For more information, see our gas appliance safety tips.