Combustion by-products are generated by fuel burning appliances and include carbon monoxide (CO), nitrogen dioxide (NO 2), and fine particles. Fuel burning appliances including gas stoves, water heaters, furnaces, and space heaters may emit these pollutants into the air you breathe. Carbon monoxide and nitrogen dioxide are both colorless odorless gases. Carbon monoxide inhalation may cause headaches, dizziness, and may lead to death. Nitrogen dioxide may cause difficulty breathing and irritation of nasal passages and mucous membranes. Very fine particulate matter may lodge in and damage the lungs.

To prevent a buildup of these harmful chemicals and particulates, be sure all fuel-burning appliances are adequately ventilated and functioning properly. Blocked chimneys and flues, cracked or disconnected flue pipes, dirty filters, rust or cracks in the heat exchanger, soot build-up, and gas odors are all indications of an indoor air quality problem. The flame of a fuel-burning appliance should burn blue. If it is yellow, it is emitting higher than normal levels of pollutants and should be adjusted. Consult an appliance service person to perform this adjustment and verify that the equipment is properly ventilated. You can also install a carbon monoxide detector to alert you of increased carbon monoxide levels.

Links to other information:

EPA’s website on combustion by-products

Montana State University Extension Service