Carbon monoxide is often called a silent killer because it’s a colorless, odorless gas that can be created by heating and cooking equipment and by vehicles or generators running in a garage.

It can poison a person either gradually via repeated exposure to small amounts or quickly by a large-scale inhalation.

“CO poisoning can be confused with flu symptoms, food poisoning and other illnesses. Some symptoms include shortness of breath, nausea, dizziness, light-headedness or headaches.”

Follow these safety tips from the National Fire Protection Association and the U.S. Consumer Product Safety Commission for preventing carbon monoxide exposure and for dealing with releases of this gas:

  • CO alarms should be installed in a central location outside each sleeping area and on every level of the home and in other locations where required by applicable laws, codes or standards. For the best protection, interconnect all CO alarms throughout the home. When one sounds, they all sound.

  • Follow the manufacturer’s instructions for placement and mounting height.

  • Choose a CO alarm that has the label of a recognized testing laboratory.

  • Call your local fire department’s non-emergency number to find out what number to call if the CO alarm sounds.

  • Test CO alarms at least once a month; replace them according to the manufacturer’s instructions.

  • If the audible trouble signal sounds, check for low batteries. If the battery is low, replace it. If it still sounds, call the fire department.

  • If the alarm sounds, immediately move to a fresh air location outdoors or by an open window or door. Make sure everyone inside the home is accounted for. Call for help from a fresh air location and stay there until emergency personnel.

  • If you need to warm a vehicle, remove it from the garage immediately after starting it. Do not run a vehicle or other fueled engine or motor indoors, even if garage doors are open. Make sure the exhaust pipe of a running vehicle is not covered with snow.

  • During and after a snowstorm, make sure vents for the dryer, furnace, stove, and fireplace are clear of snow build-up.

  • A generator should be used in a well-ventilated location outdoors away from windows, doors and vent openings.

  • Gas or charcoal grills can produce CO — only use outside.

Symptoms of CO poisoning

CO enters the body through breathing. CO poisoning can be confused with flu symptoms, food poisoning and other illnesses. Some symptoms include shortness of breath, nausea, dizziness, light-headedness or headaches. High levels of CO can be fatal, causing death within minutes.

The concentration of CO, measured in parts per million (ppm) is a determining factor in the symptoms for an average, healthy adult.

  • 50 ppm: No adverse effects with 8 hours of exposure.

  • 200 ppm: Mild headache after 2-3 hours of exposure.

  • 400 ppm: Headache and nausea after 1-2 hours of exposure.

  • 800 ppm: Headache, nausea, and dizziness after 45 minutes; collapse and unconsciousness after 1 hour of exposure.

  • 1,000 ppm: Loss of consciousness after 1 hour of exposure.

  • 1,600 ppm: Headache, nausea, and dizziness after 20 minutes of exposure.

  • 3,200 ppm: Headache, nausea, and dizziness after 5-10 minutes; collapse and unconsciousness after 30 minutes of exposure.

  • 6,400 ppm: Headache and dizziness after 1-2 minutes; unconsciousness and danger of death after 10-15 minutes of exposure.

  • 12,800 ppm: Immediate physiological effects, unconsciousness and danger of death after 1-3 minutes of exposure.

CPSC recommends consumers replace the batteries in their smoke and CO alarms annually and test the alarms monthly. Smoke alarms should be on every level of the home, outside sleeping areas and inside each bedroom. CO alarms should be installed on each level of the home and outside sleeping areas. CO alarms should not be installed in attics or basements unless they include a sleeping area. Combination smoke and CO alarms are available to consumers.

For more information, see

http://www.nfpa.org/public-education/by-topic/fire-and-life-safety-equipment/carbon-monoxide