Nitromethane Chemical Properties
- Melting point:
- -29 °C
- Boiling point:
- 101.2 °C(lit.)
- 1.127 g/mL at 25 °C(lit.)
- vapor density
- 2.1 (vs air)
- vapor pressure
- 27.3 mm Hg ( 20 °C)
- refractive index
- Flash point:
- 95 °F
- storage temp.
- Flammables area
- 10.2(at 25℃)
- APHA: ≤10
- 6.4 (0.6g/l, H2O, 20℃)
- Relative polarity
- explosive limit
- Water Solubility
- 9.5 g/100 mL (20 ºC)
- λ: 380 nm Amax: 1.00
λ: 386 nm Amax: 0.50
λ: 395 nm Amax: 0.20
λ: 400 nm Amax: 0.10
λ: 405 nm Amax: 0.05
λ: 430-700 nm Amax: 0.01
- Henry's Law Constant
- 2.24 at 20.00 °C, 3.61 at 30.00 °C, 5.40 at 40.00 °C, 7.97 at 50.00 °C (inert gas stripping, Bene? and Dohnal, 1999)
- Exposure limits
- NIOSH REL: IDLH 750 ppm; OSHA PEL: TWA 100 ppm (250 mg/m3); ACGIH TLV: TWA 20 ppm (adopted).
- CAS DataBase Reference
- 75-52-5(CAS DataBase Reference)
- NIST Chemistry Reference
- Methane, nitro-(75-52-5)
- EPA Substance Registry System
- Nitromethane (75-52-5)
- Hazard Codes
- Risk Statements
- Safety Statements
- UN 1261 3/PG 2
- WGK Germany
- Autoignition Temperature
- 784 °F
- Hazard Note
- HS Code
- Hazardous Substances Data
- 75-52-5(Hazardous Substances Data)
- LC (in air) in guinea pigs: 1000 ppm; LD50 orally in mice: 1.44 g/kg (Weatherby)
Nitromethane Usage And Synthesis
Nitromethane is a highly flammable and explosive colorless liquid with a strong, disagreeable odor.
Nitromethane is explosive and can be detonated by shock or heat (HSDB 1988) and the chemical can be made more sensitive to detonation through the presence of other chemicals, especially amines and acids. Nitromethane forms salts with inorganic bases and the dry salts are explosive.
Colorless liquid with a strong, disagreeable odor. Odor threshold concentration is 3.5 ppm (quoted, Amoore and Hautala, 1983).
Most of the nitromethane produced in the United States (85% to 90%) is used in the synthesis of nitromethane derivatives used as pharmaceuticals, agricultural soil fumigants, and industrial antimicrobials (Markofsky 1991, Angus 2001). Nitromethane also is used as a fuel or fuel additive with methanol in racing cars, boats, and model engines. It formerly was used in the explosives industry as a component in a binary explosive formulation with ammonium nitrate and in shaped charges, and it was used as a chemical stabilizer to prevent decomposition of various halogenated hydrocarbons (NTP 1997, IARC 2000, Angus 2001).
Rocket fuel; solvent for zein. Used in the coating industry.
Nitromethane and the other important nitroparaffins are synthesized commercially by the vapor-phase nitration of propane (Baker and Bollmeier 1978). At temperatures of 370-450°C and pressures of 8-12 atmospheres, nitromethane, nitroethane and 1- and 2-nitropropane are formed and then separated by distillation.
A colorless oily liquid. Flash point 95°F. May violently decompose if intensely heated when contaminated. Denser than water and slightly soluble in water. Hence sinks in water. Vapors are heavier than air. Moderately toxic. Produces toxic oxides of nitrogen during combustion.
Air & Water Reactions
Highly flammable. Slightly soluble in water.
Nitromethane may explode if heated or strongly shocked, especially if mixed with acids, bases [Handling Chemicals Safely 1980. p.687], acetone, aluminum powder, ammonium salts in the presence of organic solvents, haloforms (chloroform, bromoform), or hydrazine in methanol. Ignites on contact with alkyl aluminum or alkyl zinc halides. Reacts violently with strong bases (potassium hydroxide, calcium hydroxide), amines (1,2-diaminoethane, hydrazine), bromine, carbon disulfide, hydrocarbons, formaldehyde, metal oxides, lithium aluminum hydride, sodium hydride, strong oxidizing agents (lithium perchlorate, nitric acid, calcium hypochlorite). Reacts with aqueous silver nitrate to form explosive silver fulminate [Bretherick, 5th ed., 1995, p. 183]. Mixtures of Nitromethane and aluminum chloride may explode when organic matter is present [Chem. Eng. News 26:2257. 1948]. Nitromethane, either alone or in a mixture with methanol and castor oil, has a delayed but violent reaction with powdered calcium hypochlorite [Haz. Home Chem 1963]. Nitromethane reacts violently with hexamethylbenzene [Lewis 2544]. Nitromethane is strongly sensitized by hydrazine [Forshey, D. RR. et al, Explosivestoffe, 1969, 17(6), 125-129].
Dangerous fire and explosion risk, lower explosion limit 7.3% in air. Toxic by ingestion and inhalation. Thyroid effects, upper respiratory tract irritant, and lung damage. Possible carcinogen.
Liquid may dry out skin and cause irritation.
Nitromethane is mildly irritating to the skin and mucous membranes (Gosselin et al 1976). It produces narcosis, mucus membrane irritation and central nervous system excitation, and some liver damage. These effects are generally not as marked as after administration of nitroethane. One case of human poisoning has been reported (Kaiffer et al 1972). In that case, a handyman was exposed to high concentrations of nitrocellulose and nitromethane resulting in a 67% conversion of his hemoglobin to methemoglobin and sulfhemoglobin. Treatment with hyperbaric oxygen, transfusion, peritoneal dialysis and then 6 sessions of hemodialysis resulted in recovery.
Behavior in Fire: Containers may explode
Nitromethane is used as an intermediate in chemical syntheses, but more importantly it is used as a solvent for coatings and inks. It and the other nitroparaffins are excellent solvents for vinyls, epoxies, polyamides and acrylic polymers (Baker and Bollmeier 1978). It also is used as a military propellant and a racing fuel additive (HSDB 1988). Mixed with methanol and castor oil it is employed as a model airplane fuel.
Poison by ingestion and intraperitoneal routes. Moderately toxic by intravenous route. Mildly toxic by inhalation. In humans it may cause anorexia, nausea, vomiting, darrhea, kidney injury, and liver damage. exposed to heat, oxidizers, or flame. May explode by detonation, heat, or shock. Its sensitivity is increased when mixed with acids, bases, acetone, aluminum powder, ammonium salts + organic solvents, bis(2- aminoethyl)amine, 1,2-daminoethane + N,2,4,6-tetranitro-N-methyl aniLtne, halo forms (e.g., chloroform, bromoform), hydrazine + methanol. Ignites when mixed with alkyl metal halides (e.g., diethylaluminum bromide, dimethylaluminum bromide, ethylaluminum bromide iodide, methyl zinc iodide, methylaluminum diiodide). Can react violently with AlCl3 + organic matter, Ca(OH)2, m-methyl aniline, Ca(OCl)2, hexamethylbenzene, hydrocarbons, inorganic bases, hydroxides, organic amines, KOH, formaldehyde, nitric acid, metal oxides, 1,2-diaminomethane, litlvum perchlorate, sodium hydride. Reacts with aqueous silver nitrate to form the explosive silver fuhnate. When heated to decomposition it emits toxic fumes of NOx. See also NITROALKANES. A very dangerous fire hazard when exposed to heat, oxidizers, or flame. May explode by detonation, heat, or shock. Its sensitivity is increased when mixed with acids, bases, acetone, aluminum powder, ammonium salts + organic solvents, bis(2- aminoethyl)amine, 1,2-daminoethane + N,2,4,6-tetranitro-N-methyl aniLtne, halo forms (e.g., chloroform, bromoform), hydrazine + methanol. Ignites when mixed with alkyl metal halides (e.g., diethylaluminum bromide, dimethylaluminum bromide, ethylaluminum bromide iodide, methyl zinc iodide, methylaluminum diiodide). Can react violently with AlCl3 + organic matter, Ca(OH)2, m-methyl aniline, Ca(OCl)2, hexamethylbenzene, hydrocarbons, inorganic bases, hydroxides, organic amines, KOH, formaldehyde, nitric acid, metal oxides, 1,2-diaminomethane, litlvum perchlorate, sodium hydride. Reacts with aqueous silver nitrate to form the explosive silver fuhnate. When heated to decomposition it emits toxic fumes of NOx. See also NITROALKANES. concentrated sulfuric acid. When heated to decomposition it emits toxic fumes of NOx. See also NITRO COMPOUNDS and AMINES.
Nitromethane is used in the production of the fumigant, chloropicrin. It is best known as racing car fuel. It is also used as a solvent and as an intermediate in the pharmaceutical industry.
Nitromethane is reasonably anticipated to be a human carcinogenbased on sufficient evidence of carcinogenicity from studies in experimental animals.
Chemical/Physical. Nitromethane will not hydrolyze because it does not contain a hydrolyzable functional group.
Nitromethane is converted to nitrite and formaldehyde in a 1:1 ratio by hepatic microsomes from phenobarbital-pretreated male Sprague-Dawley rats (Sakurai et al 1980), but no formaldehyde could be detected when microsomes from the nose or liver of untreated male Fischer-344 rats were incubated with nitromethane (Dahl and Hadley 1983). Whether a similar conversion occurs in vivo has not been determined, but the absence of nitromethane metabolism in microsomes from untreated rats suggests that its metabolism in vivo may be slow.
UN1261 Nitromethane, Hazard Class: 3; Labels: 3-Flammable liquid.
Nitromethane is generally manufactured by gas-phase nitration of methane. The usual impurities include aldehydes, nitroethane, water and small amounts of alcohols. Most of these can be removed by drying with CaCl2 or by distillation to remove the water/nitromethane azeotrope, followed by drying with CaSO4. Phosphorus pentoxide is not suitable as a drying agent. [Wright et al. J Chem Soc 199 1936.] The purified material should be stored by dark bottles, away from strong light, in a cool place. Purifications using extraction are commonly used. For example, Van Looy and Hammett [J Am Chem Soc 81 3872 1959] mixed about 150mL of conc H2SO4 with 1L of nitromethane and allowed it to stand for 1 or 2days. The solvent was washed with water, aqueous Na2CO3, and again with water, then dried for several days with MgSO4, filtered again with CaSO4. It was fractionally distilled before use. Smith, Fainberg and Winstein [J Am Chem Soc 83 618 1961] washed it successively with aqueous NaHCO3, aqueous NaHSO3, water, 5% H2SO4, water and dilute NaHCO3. The solvent was dried with CaSO4, then percolated through a column of Linde type 4A molecular sieves, followed by distillation from some of this material (in powdered form). Buffagni and Dunn [J Chem Soc 5105 1961] refluxed it for 24hours with activated charcoal while bubbling a stream of nitrogen through the liquid. The suspension was filtered, dried (Na2SO4) and distilled, then passed through an alumina column and redistilled. It has also been refluxed over CaH2, distilled and kept under argon over 4A molecular sieves. It has been purified by zone melting at low temperature, or by distillation under vacuum at 0o, subjecting the middle fraction to several freeze-pump-thaw cycles. An impure sample containing higher nitroalkanes and traces of cyanoalkanes was purified (on the basis of its NMR spectrum) by crystallisation from diethyl ether at -60o (cooling in Dry-ice)[Parrett & Sun J Chem Educ 54 448 1977]. Fractional crystallisation is more effective than fractional distillation from Drierite in purifying nitromethane for conductivity measurements. [Coetzee & Cunningham J Am Chem Soc 87 2529 1965.] Specific conductivities around 5 x 10-9 ohm-1cm-1 were obtained. [Beilstein 1 IV 100.]
May explode from heat, shock, friction, or concussion. Reacts with alkalis, strong acids; metallic oxides. Detonates or reacts violently with strong oxidizers, strong reducing agents such as hydrides; formaldehyde, copper, copper alloys; lead, lead alloys; hydrocarbons and other combustibles, causing fire and explosion hazard. Forms shock sensitive mixture when contaminated with acids, amines, bases, metal oxides; hydrocarbons, and other combustible materials.
Incineration: large quantities of material may require nitrogen oxide removal by catalytic or scrubbing processes.
Nitromethane Preparation Products And Raw materials
- CYCLOHEXANONE 2,4-DINITROPHENYLHYDRAZONE
- ACID ORANGE 74
- 2-FLUORO-7-NITROFLUORENE, 99