Dinitrogen tetroxide

  • Nitrogen tetroxide
  • Nitrogen oxide
  • Nitrogen peroxide
Formula
N2O4
Structure
Description
Red-brown liquid with a sharp, unpleasant chemical odor.
Uses
Intermediate in nitric acid & sulfuric acid production, in nitration of organic compound & explosives, in manufacture of oxidized cellulose compound (hemostatic cotton), has been used to bleach flour, proposed as oxidizing agent in rocket propulsion nitrogen dioxide.

Registry Numbers and Inventories.
CAS
10544-72-6
EC (EINECS/ELINCS)
234-126-4
EC Index Number
007-002-00-0
EC Class
Very toxic; Corrosive
RTECS
QX1575000
RTECS class
Other
UN (DOT)
1067
Beilstein/Gmelin
2249 (G)
RCRA
P078
Canada DSL/NDSL
NDSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
N2O4
Formula mass
92.01
Melting point, °C
-15
Boiling point, °C
21.2
Vapor pressure, mmHg
123.4 (-10.9 C)
Vapor density (air=1)
1.58
Critical temperature
158
Critical pressure
0.13
Density
1.43958 g/cm3 (21.64 C)
Solubility in water
Reacts
Viscosity
0.418 cp (20 C)
Surface tension
27.5 g/s2 at 19.8 C
Heat of fusion
12.40 kJ/mol
Heat of vaporization
38.12 kJ/mol

Hazards and Protection.
Storage
Store in a cool, dry, well ventilated location. Separate from oxidizable materials. Outside or detached storage is preferred.
Handling
All chemicals should be considered hazardous. Avoid direct physical contact. Use appropriate, approved safety equipment. Untrained individuals should not handle this chemical or its container. Handling should occur in a chemical fume hood.
Protection
Wear special protective clothing and positive pressure self-contained breathing apparatus.
Respirators
Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode. Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained breathing apparatus operated in pressure-demand or other positive-pressure mode.
Small spills/leaks
Neutralizing Agents for Acids and Caustics: Flush with water, then use soda ash or lime.
Stability
No data.
Incompatibilities
Reacts with reducing agents to generate heat and products that may be gaseous (causing pressurization of closed containers) Reacts with alkalis to form nitrates and nitrites Reacts explosively with liquid ammonia even at very low temperatures (below its freezing point) Reacts energetically with boron trichloride Mixtures with metal carbonyls are hypergolic (enflame immediately) Mixtures with halocarbons, hydrazine derivatives, heterocyclic bases (pyridine), isopropyl nitrite/propyl nitrite, active metals (magnesium, calcium, etc.), nitroaromatics, nitrogen trichloride, phosphorus, triethylamine, unsaturated hydrocarbons
Decomposition
When heated to decomposition it emits toxic fumes of oxides of nitrogen.

Fire.
Fire fighting
Fire Extinguishing Agents: Stop flow of gas
Fire potential
Substance does not burn but will support combustion.
Hazards
When heated to decomposition, toxic fumes of nitrogen oxides are emitted. May ignite other combustible materials (wood, paper, oil, etc.). Mixture with fuels may explode. Container may explode in heat of fire. Vapor explosion and poison hazard may occur indoors, outdoors or in sewers. Decomposes in water, forming nitric acid and nitric oxide. Avoid moisture and physical damage to storage container. Incompatible with combustible matter, chlorinated hydrocarbons, ammonia, carbon disulfide. Reacts with alkalies to form nitrates and nitrites. Violent reaction with cyclohexane, fluorine, formaldehyde, alcohols, nitrobenzene, petroleum, and toluene.
Combustion products
Produces toxic gas when heated.
Health
3
 
Flammability
0
 
 
Reactivity
0
 
 
Special
O

Health.
Exposure effects
Fatigue, restlessness, anxiety, mental confusion, lethargy, and loss of consciousness may be noted.
   Ingestion
Nausea, vomiting and abdominal pain may develop.
   Inhalation
Nitrogen oxides react with water in the respiratory tract to slowly form nitric and nitrous acid. Cough, hyperpnea and dyspnea will be seen. Rapid and shallow respirations, mild or violent coughing and physical signs of pulmonary edema may develop. Pulmonary edema may be delayed 4 to 24 hours.
   Skin
Cyanosis may occur.
   Eyes
Inflammation of the eye may occur.

First aid
 
   Ingestion
Seek medical assistance.
   Inhalation
Remove patient to fresh air and have him breathe as deeply as possible; call a doctor; enforce complete rest for 24-48 hours; keep warm; give oxygen if coughing starts; physician may administer morphine (10 mg.)
   Skin
Flush with water for at least 15 min.
   Eyes
Immediately flush with running water for at least 20 minutes. Effects may be delayed.

Transport.
UN number
1067
Response guide
Hazard class
2.3
PRTC
T
USCG CHRIS Code
NOX
 
Std. Transport #
4920174