Fire Prevention 52: Carbon Monoxide, A Breath of Death

During fall and winter, chances of inhaling this poisonous gas increase and with it the risk of sudden illness, permanent brain damage, cardiac complications, or death. Annually, 500 people die and 15,000 are made seriously ill by its effects.

white carbon monoxide alarm on the ceiling
Install CO alarms outside each sleeping area and on every level of the home where bedrooms are located.

The night was too cold and windy to enjoy the traditional warmth of an evening campfire, so my family huddled around the table in our pop-up trailer and dealt cards under the light of a propane lantern. Halfway through the card game, we heard buzzing and soon realized the carbon monoxide (CO) detector near the floor of the trailer was alerting us. We quickly ushered the kids out of the trailer, turned the lantern off, and opened the windows for increased ventilation. Whew --what a close call!

Why the concern?

CO is an odorless, colorless gas produced whenever any fuel, such as gas, oil, kerosene, wood, charcoal, or, in our case, propane is burned. When inhaled, it's absorbed into the bloodstream, where it limits blood's ability to carry oxygen. CO forms a strong bond with hemoglobin in the blood and, once bonded, cannot be dislodged. As more CO is inhaled, life-sustaining oxygen does not reach your muscles, organs, and tissues. Eventually, a person suffocates, even though oxygen is still in the air.

What are the symptoms of CO poisoning?

Symptoms of exposure can begin with a dull headache and quickly move to weakness, dizziness, nausea, vomiting, shortness of breath, confusion, blurred vision, and eventually loss of consciousness. CO poisoning can be mistaken for the flu or food poisoning, because the symptoms are similar. However, if the symptoms come on suddenly, CO should be considered.

Where is CO found around the home? The following appliances and equipment are sources of CO:

  • Fuel-fired furnaces and fuel-burning space heaters
  • Gas water heaters, stoves, and clothes dryers
  • Fireplaces and wood stoves
  • Charcoal grills
  • Portable generators
  • Automobiles and boats
  • Lawn mowers, snow blowers, and other yard equipment

If appliances that burn fuel are maintained and used properly, the amount of CO produced is usually not hazardous. However, if appliances are not working properly or are used incorrectly, dangerous levels of CO can result.

Who is the most vulnerable to CO poisoning?

  • Unborn babies, whose blood cells absorb CO more readily than an adult's
  • Infants and children, who take breaths more frequently than adults
  • Senior citizens, who are more likely to develop brain damage from inhaling CO
  • Individuals already compromised by heart or lung problems

Back at the campground, we thought the thin fabric of the pop-up trailer was well ventilated, but obviously not enough to prevent a buildup of dangerous CO fumes from the propane lantern. We were grateful that the CO detector alerted us to danger.

Fire Info for You

Download the National Fire Protection Association's carbon monoxide safety flyer for tips on installing CO detectors and preventing CO buildup when using fuel-burning appliances.

Structural Firefighters
Watch The Silent Killer to learn about CO poisoning risks to firefighters during overhaul operations. The International Association of Fire Chiefs also offers resources pertinent to firefighters.

Park Leadership
Ensure heating systems are inspected each year in park buildings. Consider installing CO detectors in park residences and seasonal quarters.

Take Action

  1. Install CO alarms outside each sleeping area and on every level of the home where bedrooms are located. Change the batteries biannually at the same time as your smoke detectors.
  2. Have your heating system inspected by a qualified technician every year.
  3. Evacuate your home when a CO detector sounds and call 911.

NPS Fire Facts

Employees who work in areas where boating is popular know that it's not uncommon for CO to collect within, alongside, or behind boats in minutes, mainly near exhaust vents from inboard engines, outboard engines, and generators.

In one summer incident, Glen Canyon National Recreation Area treated 34 visitors for CO poisoning when they were exposed while swimming to exhaust from a generator vented underwater. Some of the children were found unresponsive by their parents, and the adults complained of dizziness, nausea, and headaches. Fortunately, park employees had recent training highlighting a similar scenario and the park was prepared with the appropriate equipment. Of the 34 people taken to the local clinic, 21 required oxygen therapy for high CO levels in their blood.

Last updated: November 25, 2016