Nitrogen dioxide / NO₂
Threshold limit value
Nitrogen dioxide : Description and use
Nitrogen dioxide is a precursor in the industrial production of nitric acid (HNO₃) and a major pollutant of Earth's atmosphere. It is produced by internal combustion engines and thermal power stations. As such, it is responsible for the acidifying and eutrophying nature of sulphur-free "acid rain" (NO₂ combined with the anthropogenic tropospheric ozone forms nitrates which are highly soluble in water).
In its concentrated form, it is a suffocating and toxic reddish-brown gas with a characteristically acrid and pungent odour. Due to being highly volatile (a boiling point of 21°C, i.e. very close to room temperature), this product is generally delivered in cylinders as a liquefied compressed gas.
Flammability and explosiveness: Nitrogen dioxide is non-flammable. However, it is a combustion agent which can react aggressively with several compounds, which may cause fires and explosions.
- Nitrating agent (among other things, to manufacture nitric acid and liquid explosives)
- Oxidising agent (for example, as a bleaching agent for flour)
- Combustion agent (for rocket fuels in particular)
- Catalyst for some oxidisation reactions
- Polymerisation inhibitor when distilling acrylates
- Component in calibration gas mixtures for atmospheric pollution control and combustion gas control
Nitrogen dioxide : Warnings and caution
H270 - May cause or intensify fire; oxidiser.
H280 - Contains gas under pressure; may explode if heated.
H314 - Causes severe skin burns and eye damage
H330 - Fatal if inhaled.
EUH071 - Corrosive to the respiratory tract.
P260 - Do not breathe vapours.
P284 - Wear respiratory protection.
P304+P340 - IF INHALED: Remove victim to fresh air and keep at rest in a position comfortable for breathing.
P310 - Immediately call a POISON CENTRE or doctor/physician.
Nitrogen dioxide : Related products
Multi-Gas Area Monitors
Fixed Gas Detectors