Nitrogen Dioxide Detection

Nitrogen dioxide is the chemical compound with the formula NO₂. It exists as a radical in nature. One of several nitrogen oxides, NO₂ is an intermediate in the industrial synthesis of nitric acid, of which millions of tonnes are produced each year.

 

This reddish-brown toxic gas has a characteristic sharp, biting odour and is a prominent air pollutant. Nitrogen dioxide typically arises via the oxidation of nitric oxide by oxygen in air.

 

Nitrogen dioxide is toxic by inhalation, but toxic effects can be avoided as the material is acrid and easily detected by our sense of smell. One potential source of exposure is fuming nitric acid, which spontaneously produces NO₂ above 0°C. Symptoms of poisoning (generally lung oedema) tend to appear several hours after one has inhaled a low but potentially fatal dose.