Each year about 500 people die in the United States from unintentional exposure to carbon monoxide (CO), the silent, odorless, colorless gas formed by incomplete combustion of fuels.

CO can build up to dangerous concentrations indoors when fuel-burning devices—furnaces, water heaters, gas or kerosene space heaters, gas boilers, gas ranges and ovens, gas dryers, charcoal or gas grills, fireplaces and wood stoves, motor vehicles, and yard equipment—are not properly vented, operated or maintained. CO is most common in the winter months, when a heating system malfunctions in a home or when a car engine is left running in a garage. You can also become exposed to high levels of CO while camping, fishing, hunting, and boating. For instance, CO can form in the cabin areas of boats or in ice houses with heating equipment.

The Minnesota Department of Health offers three basic tips to prevent CO poisoning: 

    1. Properly vent and maintain fuel-burning appliances

All fuel-burning appliances should be vented to the outside and should be checked by a qualified heating contractor every year to detect potential problems. Never use appliances intended for outdoor use inside, such as barbecue grills, camp stoves, or portable generators. Do not idle cars in garages, both attached and unattached, for any length of time. Dangerously high levels of CO can accumulate even if the garage door is open.

    2. Know the symptoms of CO poisoning

When CO is inhaled into the lungs it displaces the oxygen in the blood stream and affects all major organs and muscles. Symptoms of CO exposure are similar to flu-like symptoms. For most people, the first signs of CO exposure include mild headache and breathlessness with moderate exercise. Continued exposure can lead to more severe headaches, dizziness, fatigue, and nausea. Some ways to distinguish CO poisoning from the flu:

• You feel better when you are away from home.
• Everyone in the home is sick at the same time.
• Family members most affected spend the most time at home.
• You don’t have a fever or body aches that come with the flu.

    3. Install and maintain CO alarms in your home

Minnesota state law requires that every home have at least one operational CO alarm within 10 feet of every room legally used for sleeping. All CO alarms should conform to the latest Underwriters Laboratory (UL) Standards. Follow the manufacturer’s instructions for placement of your CO alarms, and take note of the suggested replacement date.

For more information on CO poisoning, visit the Minnesota Department of Health website and the Carbon Monoxide Safety Association at www.cosafety.org.

Minnesota Energy Tips is provided twice a month by the Minnesota Department of Commerce, Division of Energy Resources. Contact the division’s Energy Information Center at energy.info@state.mn.us or 800-657-3710 with energy questions.