Preventing Carbon Monoxide (CO) Poisoning in Your Home

• How can I prevent carbon monoxide (CO) from reaching dangerous concentrations in my home?
• When should I have my fuel-burning appliance inspected?
• What is a CO alarm?
• Will a CO alarm sound at all unsafe concentrations?
• Is a CO indicator card a reliable substitute for an alarm?
• What should I look for when buying a CO alarm?
• Where should I place my CO alarm?
• What should I do if the alarm goes off?
• Can I have a false alarm?
• For more information

How can I prevent carbon monoxide (CO) from reaching dangerous concentrations in my home?

Prevention is the key. The following steps should protect you.

• Install a CO alarm that will warn you before dangerous concentrations of CO are reached.
• Make sure combustion (fuel-burning) appliances are installed and working according to manufacturers’ guidelines—it’s especially important that the devices have an adequate air supply and exhaust directly to the outdoors.
• Have combustion appliances inspected every year.
• Make sure all flues, chimneys, and exhaust vent pipes are connected properly, in good condition, and unobstructed.
• Install and use an exhaust fan over your gas stove that is vented to the outside.
• Open the chimney flue fully when using the fireplace.
• Make sure doors on fuel-burning stoves fit properly and are closed tightly.
• Use the proper fuel in kerosene space heaters.
• Consider purchasing a vented space heater when replacing unvented ones.
• Never use your cooking stove to heat your home.
• Don’t ever burn charcoal inside your home or in any enclosed space.
• Don’t sleep in any room with an unvented gas or kerosene space heater.
• If you have an attached garage, don’t idle your vehicle in it—back it out right away.
• If you are using a paint remover containing methylene chloride, follow manufacturer’s instructions and perform work in a well-ventilated area.

Go to > top.

When should I have my fuel-burning appliance inspected?

You should have your fuel burning appliances professionally checked annually by a qualified technician. Look for a qualified technician in your Yellow Pages under “Heating Contractors”. The Minnesota Department of Commerce Energy Information Center has recommendations for heating contractors. Call 651-296-5175 or 1-800-657-3710 for additional information.

Go to > top.

What is a CO alarm?

CO alarms sound an audible alarm to warn building occupants when CO concentrations are high enough to be a health concern. Smoke alarms detect smoke particles—they won’t sound a warning for CO alone.

Go to > top.

Will a CO alarm sound at all unsafe concentrations?

CO alarms warn occupants if CO accumulates to a concentration that poses an immediate hazard. However, CO alarms typically do not sound at lower concentrations that may also be unhealthy if breathed for a long time. In addition, sometimes CO alarms will fail to sound even at high concentrations. The most protective approach, therefore, is to use CO alarms along with operating, venting, and maintaining all combustion appliances appropriately.

Go to > top.

Is a CO indicator card a reliable substitute for an alarm?

CO indicator cards change color when a specified concentration of CO is present. They do not provide an audible alarm to warn occupants when they are asleep. In addition, one would need to notice the color change. Therefore, MDH recommends using a CO alarm to avoid these problems.

Go to > top.

What should I look for when buying a CO alarm?

The Consumer Product Safety Commission recommends every home have at least one CO alarm that meets the requirements of the most recent Underwriters Laboratories (UL)
2034 standard, International Approval Services (IAS) 6-96 standard or the
Canadian Standards Association 6.19-01 standard. Look on the package for these designations.

Because the alarm should be capable of waking you up while you sleep, make sure it will be loud enough for how you intend to use it. Consider the power source options where you want to place the alarm. These devices can be battery powered, hard-wired into your home’s electrical system, or plugged into a standard 110V electrical outlet. Select an alarm that can be tested and reset easily. Remember that battery-powered alarms should be tested frequently (generally every week) and the batteries replaced at least yearly. Hard-wired devices should also be tested as directed, usually on a monthly basis.

CO alarms are available at discount stores, hardware stores, and building supply stores. Many utility companies also sell them to their customers. Expect to pay between $35 and $60 for a UL listed CO alarm. Save package instructions for future reference.

Go to > top.

How many CO alarms should I have?

MDH recommends having at least one functioning CO alarm for every level of your home. At a minimum, make sure that you have one CO alarm for every level of your home with a bedroom.

Go to > top.

Where should I place my CO alarm?

Where to locate a CO alarm depends on your home’s layout as well as the type and location of the fuel-burning appliances. Follow the manufacturer’s recommendations for installation and placement. Typically, you should place at least one alarm near the bedrooms to alert people sleeping. If multiple rooms are used for sleeping, locate the detector in a common area where it can be heard from each.

Locate the alarm at least 5 feet away from sources of household chemicals because chemicals released from many household products can damage the alarm’s sensor. Also, do not place a CO alarm on or very near combustion appliances since they can emit CO in short bursts when they are first turned on. Consult the manufacturer’s instructions for further advice on device placement and maintenance.

Go to > top.

What should I do if the alarm goes off?

Never ignore the alarm! A rapid response may save lives. It is very important that all household members know what to do if the CO alarm sounds.

If the alarm goes off and anyone is experiencing flu-like symptoms:

• Immediately evacuate everyone from the home and
• Call 911 from outside the home.

If the alarm goes off, but no one has flu-like symptoms:

• Air out the home by opening doors and windows;
• Turn off all fuel-burning appliances;
• Reset you CO alarm—if elevated levels remain, UL listed alarms will sound again after 6 minutes; and
• Call a qualified Heating Contractor to inspect for sources of CO. Do not operate fuel-burning appliances until they have been inspected.

Go to > top.

Can I have a false alarm?

False alarms can occur; however, you should always initially respond as if CO danger is real. Some common household chemicals and cleaning supplies may trigger a false alarm. The alarm may also sound when there are problems with its power supply. Contact the device manufacturer if false alarms occur repeatedly.

Go to > top.

For more information read the Carbon Monoxide (CO) Poisoning in Your Home fact-sheet.

Further information can be obtained from:

• Minnesota Department of Health, Indoor Air Unit
  625 Robert St N
  PO Box 64975
  St. Paul, MN 55164-0975
  Phone: 651-201-4601 or 1-800-798-9050
• Your gas utility:
  • Xcel Energy: 651-282-1200.
  • Reliant Energy-Minnegasco: 612-342-4610 or 1-800-333-9365
• For questions regarding your combustion appliances contact the Minnesota Department of Commerce, Energy Information Center: 651-296-5175 or 1-800-657-3710.
• For question about specific products contact the Consumer Product Safety Commission (CPSC): 1-800-638-2772 or 1-800-638-8270.
• Contact your Fire Department to learn what services they provide. Some offer free inspection of combustion appliances.

Go to > top.

For questions about this page or indoor air quality, please contact the Indoor Air Unit at health.indoorair@state.mn.us, 651-201-4601 or 800-798-9050.