Nitrogen Dioxide Detection

Nitrogen Dioxide Detection

Nitrogen Dioxide

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.
 
Air-Met has several solutions for detection of nitrogen dioxide. Contact your local Air-Met Scientific office for more information.
 
Nitrogen Dioxide Characteristics
Synonyms  
CAS No. 10102-44-0
Chemical formula NO2
Vapour density 1.58 (air = 1)
Safe Work Australia ES TWA 3 ppm
STEL 5 ppm
Flammable limits LEL ---
UEL ---
Equipment group ---
Temperature classification ---
Chemical/physical properties At room temperature, nitrogen dioxide is a reddish-brown, non-flammable gas with a pungent, acrid odour. Below its boiling point of 21.2°C, it is a pale yellow liquid. 
Hazardous properties Nitrogen dioxide is a powerful lung irritant leading to pulmonary oedema. Exposure to concentrations in the range of 100 to 500 ppm may lead to death from respiratory failure.
Occurrence/Uses Like nitric oxide, nitrogen dioxide is produced due to oxidation of atmospheric nitrogen at high temperatures during combustion, welding and the detonation of explosives.
It is also present in “silo gas” when silage is being stored due to the oxidation of nitric oxide in air.
Detectors available Electrochemical (0–150 ppm)
Gas detector tube (0.1–1,000 ppm)
Suggested alarm levels Lo: 3 ppm
Hi: 5 ppm
Notes