How to look for signs associated with carbon monoxide poisoning and how to check your heating and cooking appliances for CO production.
Carbon monoxide (CO) is a colorless and odorless gas that is formed when carbon-based fuels, such as kerosene, gasoline, propane, natural gas, oil, charcoal or wood, are burned with inadequate amounts of oxygen, creating a condition known as incomplete combustion. In the case of home appliances, this can be caused by improper installation, poor maintenance, appliance misuse or failure. This article will deal with the most common fuel found in the home, natural gas, but most of the information is applicable for propane.
Carbon Monoxide Poisoning
When a heating or cooking appliance has insufficient oxygen available incomplete combustion occurs and carbon monoxide is produced. Depending on the amount of carbon monoxide produced, carbon monoxide poisoning can occur to anyone inside the building. The early stages of carbon monoxide poisoning produce unexplained flu-like symptoms, such as headaches, dizziness, nausea, vomiting, shortness of breath and mental confusion. Carbon monoxide displaces the oxygen in the blood so prolonged exposure can lead to death.
Everyone is at risk for carbon monoxide poisoning. Some individuals may be more vulnerable such as pregnant women, infants, children, senior citizens, and people with heart of lung problems.
How to maintain and use gas appliances to prevent carbon monoxide
If you are unfamiliar with heating or cooking appliances you should have your gas appliances inspected annually by a licensed, qualified professional or a service technician from your natural gas supplier.
• Vacuum around burner compartments, and inspect and replace furnace filters on forced-air units or central heating systems according to manufacturer instructions. (Caution: Make sure that the burner and gas supply are shut off. Review start-up procedures for your appliance if you need to relight a pilot light.)
• Make sure to properly replace the front panels of a forced-air unit or the burner compartment door of a gas wall heater.
• Never store anything near a gas appliance that might interfere with normal airflow.
• Assure that appliance venting is intact and unblocked. Have all gas appliances and venting repairs done by a licensed, qualified professional.
• In higher altitude areas, where snow can accumulate on rooftops, ensure that gas appliance intake and exhaust vents are clear of obstructions.
• When using your gas fireplace, make sure the damper is open.
• Never use your gas oven for space heating.
• Gas appliance maintenance is always the homeowner’s responsibility. However, many natural gas suppliers will perform appliance safety checks upon request.
• Never store or use flammable products in the same room or near any gas or heat-producing appliances. Flammable products include gasoline, spray paints, solvents, insecticide, adhesives, foggers, varnish, cleaning products and other pressurized containers.
• Never store rags, mops, paper or other combustibles near any gas appliance.
CO dangers in the home
There are a few clues that you need to look for that will tell you if your appliance is not functioning properly and may lead to carbon monoxide production.
• Large, yellow, and unsteady burner flame. This does not include decorative gas log appliances.
Gas flame characteristics
• An unusual pungent odor when the appliance is operating. This may indicate the creation of aldehydes, a by-product of incomplete combustion. This toxic gas is detectable by smell and gives the sensation of a metallic taste after exposure and indicates CO is most likely present. Unusual odors may also indicate that some other substance, such as volatile organic compounds (VOC) is being pulled into the burner. While this may not produce CO, it may pose an elevated risk for fire or illness depending on the substance. Some common VOCs are fumes from paints or sealants and household cleaners.
• Unexplained nausea, drowsiness irritability, and flu-like symptoms.
• Excessive soot production around the unit and access panels.
• Condensation forming on windows and cool surfaces during operation.
• Dead Plants - Dangerous levels of CO are likely if the plants in your home have died or are severely withered.
Appliance service and adjustment is needed if any of these visible signs of incomplete combustion are noticed.
What to do
• If safe to do so, immediately turn off the suspected gas appliance.
• Evacuate the premises and call 911.
• Seek medical attention if anyone in the home experiences possible carbon monoxide poisoning symptoms.
• Contact your natural gas supplier or a licensed, qualified professional immediately to have the appliance inspected.
• Don’t use the suspected gas appliance until it has been inspected, serviced and determined to be safe by a licensed, qualified professional.
Other Safety Tips
Although your appliances may have been up-to-date when they were installed, the codes in your area may have changed. Even though most municipalities allow certain installations to be grandfathered into service, you may want to make sure that you are in compliance with your building department, fire marshal, and home owner’s insurance policy.
Carbon monoxide home alarms
Carbon monoxide alarms may provide an extra level of safety, but they also require routine maintenance and replacement at least every three to five years to perform properly. Even with alarms in place, regular gas appliance maintenance is still required. Inspection and routine maintenance are still the best defense against accidental carbon monoxide poisoning from natural gas appliances.
There are several different models of gas-fired furnaces and you should be familiar with the operation of your equipment.
• Most gas furnaces use air from the room to operate. Lint and dust carried by air, or items stored in or around the furnace can block airflow. In order to operate safely and efficiently, your gas furnace must be kept free of dust and lint build-up or other obstructions stored near the furnace, such as newspapers or cleaning equipment.
• The filter should be checked monthly for lint build-up during periods of furnace use and cleaned or replaced if necessary.
• When installing a new or cleaned filter, be sure to re-install the front panel door of the furnace properly so it fits snugly. Never operate the furnace without the front-panel door properly in place because doing so may create the risk of carbon monoxide poisoning. Older units may not come equipped with a safety switch that will prevent the furnace from running with the access panel removed.
• All gas water heaters have a main burner flame and many also have a standing pilot flame. To reduce the risk of flammable vapors being ignited by these flames, follow these tips:
o Water heaters installed in garages must be elevated so the pilot or other source of ignition is a minimum of 18 inches above the floor or installed per local building codes or the manufacturers’ installation instructions.
• Never store or use flammable products such as gasoline, paint thinner or cleaning products in the same room or near any gas or heat-producing appliance.
• If you live in an area where earthquakes are possible, make sure that the water heater is properly secured to the building structure at the top and bottom. Kits are often available at your local home center or hardware store.
Ranges and Ovens
• Never use your range or oven to heat your home because these appliances are not designed for this purpose.
• Keep burners and the range top clean. Accumulations of grease can create a fire hazard.
Natural Gas Fireplace Logs
• To help avoid serious accidents, the damper must be kept open on a permanent basis.
Unvented Room Heaters
Avoid using unvented room heaters. They are illegal to use in many states.
• Poor operation can result in an accumulation of hazardous fumes.
• Unless a room heater has enough air from an outside vent or an open window, all of the oxygen in a room can be used up, resulting in serious illness or death.
• The flames may be partially exposed which could result in injuries or fires.
Appliance Safety Recalls
The U.S. Consumer Product Safety Commission (CPSC) periodically announces safety recall programs for certain gas appliances and equipment. Information about product recalls that may affect your appliances is available at the CPSC Web site (www.cpsc.gov ) or by calling the CPSC at 1-800-638-2772.