Nitrogen Dioxide

Nitrogen dioxide (NO2) is a red-brown gas produced when fuel burns. It is present in vehicle exhaust and the fumes from burning fuel oil, kerosene, propane, natural gas or wood. Appliances such as gas stoves, portable heaters, fireplaces, and gas-fueled clothes dryers may produce this gas. When NO2 is exposed to water, it can form nitric acid, which is a chemical that contributes to acid rain. Nitrogen dioxide is also a major cause of smog.

How can I avoid being exposed to nitrogen dioxide?

Have gas appliances professionally inspected each year.

Be sure that all gas appliances are properly vented to the outdoors.

Keep fireplace flues fully open and clear of obstructions when in use.

Never idle a car inside a garage or car port.

Make sure that wood stoves are correctly installed and vented.

Have your home heating system and chimney professionally inspected each year.






What should I do if I suspect a problem?

If you suspect NO2 exposure, and can identify the source (e.g., a gas engine), turn off the source and get fresh air into the area. Open windows and doors. Use a fan if necessary to increase air circulation.

If you experience unexplained symptoms such as cough, fatigue, eye and nose irritation that go away when you leave home, NO2 poisoning may be occurring in your home.

Elderly people, young children, and people with chronic respiratory diseases such as asthma and emphysema may be very sensitive to NO2; they should be evacuated. If the symptoms are causing discomfort or if they are persistent, consult your doctor.

If you suspect that a device in your home, such as a stove, is releasing NO2, call your local gas utility or a heating contractor for a home inspection. Once the NO2 source is identified, repair, replacement, or proper ventilation of the appliance can eliminate the problem.

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Last Revised: March 13, 2017