Healthy Homes: Reduce Combustion Make an Appointment Ask a Question Search Conditions Step 1: Learn about combustion Combustion pollutants are gases or particles that come from appliances that use natural gas such as furnaces, hot water heaters and gas stoves. Combustion pollutants include: Carbon Monoxide: Breathing carbon monoxide causes symptoms such as headaches, dizziness and weakness in healthy people. At high levels, carbon monoxide causes loss of consciousness and death. Nitrogen Dioxide: Breathing nitrogen dioxide causes lung irritation and can make asthma symptoms worse. All gas appliances must be properly maintained and vented to the outside to prevent the release of combustion pollutants indoors. Carbon monoxide is odorless and some of the symptoms are similar to common illnesses. Step 2: Take action Never use a natural gas range (stove), oven, or dryer to heat your home - they can produce fatal amounts of carbon monoxide. Never use a portable propane, kerosene, or gas heater indoors – they can also produce fatal amounts of carbon monoxide. Make sure you have a working carbon monoxide detector near your sleeping area. Never ignore the smell of fuel. This usually indicates that the appliance is not operating properly or is leaking fuel. If you suspect that you have a fuel leak, leave the house and call your local power company as soon as possible. Check the flames in your furnace combustion chambers and pilot lights on gas water heaters and gas cooking appliances. Natural gas appliances should have a blue flame with perhaps only a slight yellow tip. Call your appliance service representative to adjust the burner or pilot light if there is a lot of yellow in the flame. Always use the exhaust fan or open a window when using a gas range (stove). Even properly working gas stoves can release enough nitrogen dioxide to make asthma symptoms worse.