メチルイソシアナート 化学特性,用途語,生産方法
用途
医薬?農薬中間体 (化学工業日報社)
説明
Methyl isocyanate (MIC) is an organic compound with the
molecular formula CH3NCO. MIC is an extremely toxic,
colorless, highly flammable liquid that evaporates quickly
when exposed to the air and has a sharp, strong odor. It is
hazardous to human health, and was involved in the Bhopal
disaster in December 1984, which resulted in the deaths of
more than 2250 individuals, with another 50 000 incapacitated,
and about 100 000 treated in area hospitals.
化学的特性
colourless liquid
物理的性質
Clear, colorless, very flammable, posionous liquid with a sharp, unpleasant, penetrating odor.
Odor threshold concentration is 2.1 ppm (quoted, Amoore and Hautala, 1983).
使用
In organic synthesis; in manufacture of carbamate pesticides.
調製方法
Methyl isocyanate is
reacted with 1-naphthol to produce the carbamate insecticide
carbaryl and with α-methylthioisobutyrladoxime in the
industrial synthesis of aldicarb.
定義
ChEBI: The isocyanate that is methane modified by a single isocyanato substituent.
空気と水の反応
Highly flammable. Reacts exothermically with water to produce carbon dioxide, methylamine, dimethylurea and/or trimethylbiuret. Heat of reaction causes evolution of the vapors of the isocyanate. Reaction is relatively slow below 20°C but becomes violent at more elevated temperatures or in the presence of acids and bases.
反応プロフィール
Airborne vapors of METHYLISOCYANATE 1 X 500MG NEAT are explosive when exposed to heat, flame or sparks. Vapor may ignite on contact with strong oxidizing agents. Emits toxic fumes of nitriles and oxides of nitrogen when heated to decomposition [Lewis, 3rd ed., 1993, p. 860]. Caused the death of thousands in 1984 in Bhopal, India when released accidentally as a vapor following an exothermic reaction caused by contamination with water [Chem. Eng. News, 1985, 63(6), p. 27]. Reacts rapidly with acids and bases (including amines). May polymerize in contact with iron, tin, copper and certain other catalysts such as triphenylarsenic oxide, triethyl phosphine and tributyltin oxide. Polymerizes at elevated temperatures. Attacks some plastics, rubbers, and coatings [NTP].
危険性
Flammable, dangerous fire risk. Toxic byskin absorption and a strong eye and upper respira-tory tract irritant.
健康ハザード
METHYLISOCYANATE 1 X 500MG NEAT is a skin irritant and can cause permanent eye damage. A concentration of 2 ppm has been reported toxic in humans. METHYLISOCYANATE 1 X 500MG NEAT attacks the respiratory system, eyes and skin. It can injure the lungs and bronchial airways, cause permanent eye damage, and death. Death has been attributed to various forms of respiratory distress.
火災危険
Reacts violently with water. Extremely flammable; may be ignited by heat, sparks, or flames. Vapors may travel to a source of ignition and flash back. Container may explode violently in heat of fire. Vapor explosion and poison hazard indoors, outdoors, or in sewers. Runoff to sewer may create fire or explosion hazard. When heated to decomposition, METHYLISOCYANATE 1 X 500MG NEAT emits toxic fumes of nitrogen oxides. Avoid water, acids, alkali, amines, iron, tin, copper, and other catalysts. Avoid heat, flame, oxidizers, water. Hazardous polymerization may occur. METHYLISOCYANATE 1 X 500MG NEAT (MIC) will react with water, or in the presence of catalysts (such as sodium hydroxide, sodium methoxide, triphenylarsine, triethyl phosphine, metallic chlorides) to form either a cyclic trimer (trimethyl isocyanurate) or a gummy, resinous polymer. These reactions are exothermic, producing about 540 Btu per pound of MIC. Heat produced in these reactions may result in pressure build up and rupturing of tanks.
安全性プロファイル
Poison by inhalation,
ingestion, and skin contact. Human systemic
effects by inhalation: conjunctiva irritation,
olfactory and pulmonary changes. An
experimental teratogen. Other experimental
reproductive effects. Mutation data reported. A severe eye, skin, and mucous
membrane irritant and a sensitizer. It can be
absorbed through the skin. Exposure to
high concentrations of the vapor can cause
blindness; lung damage, including edema,
permanent fibrosis, emphysema, and
bronchitis; and gynecological effects. Most
deaths are a result of lung tissue damage.
This was the predominant cause of death in
the release of MIC in 1984 at Bhopal, India.
Effects of cyanide poisoning have been
noted but this may be due to impurities. A
flammable liquid and a very dangerous fire
hazard when exposed to heat, flame, or
oxiduers. To fight fire, use spray, foam,
CO2, dry chemical. Exothermic reaction
with water. When heated to decomposition
it emits toxic fumes of NOx and CN-.
職業ばく露
Methyl isocyanate is used in carbamates and as chemical intermediate; in the manufacture
of a wide variety of pesticides; in the production of polyurethane foams and plastics. A release of this chemical was
involved in the world’s largest chemical accident, causing
the death of thousands of industrial workers in 1984
in Bhopal, India.
発がん性
Genetic and Related Cellular Effects Studies.
Mason et al. found that methyl isocyanate did not induce
mutagenic response in the Salmonella assay under test
conditions. It was also negative in the Drosophila test for
sex-linked recessive lethal mutations; however, it was positive
in the cultured CHO cells. Mason et al. found that
methyl isocyanate was positive in the mouse lymphoma
assay.
環境運命予測
Chemical/Physical. Reacts with water forming 1,3-dimethylurea and carbon dioxide. In excess
water, the hydrolysis half-life is 9 min. (Castro et al., 1985)
輸送方法
UN2480 Methyl isocyanate Hazard class: 6.1;
Labels: 6.1-Poison Inhalation Hazard, 3-Flammable liquid,
Inhalation Hazard Zone A
不和合性
Highly flammable liquid. Vapors may
form explosive mixture with air. Rapid reaction in presence
of acid, alkalis, amine; iron, tin, copper, their salts; or their catalysts (such as triphenylarsenic oxide, triethylphosphine,
and tributyltin oxide). Exothermic reaction with water, producing carbon dioxide, highly flammable and air-reactive
methylamine, dimethylurea and/or trimethyl biuret. The
reaction with water is slow @ # 20C, but violent at
elevated temperatures and/or in the presence of acids
and bases. Elevated temperatures may cause explosive
polymerization. This chemical usually contains inhibitors to
prevent polymerization. Reacts with water, acids, alcohols,
glycols, amines, amides, ammonia, caprolactum, caustics,
strong oxidizers. Attacks some plastics, rubber or coatings.
Attacks some forms of plastic, rubber and coatings
廃棄物の処理
Consult with environmental
regulatory agencies for guidance on acceptable disposal
practices. Generators of waste containing this contaminant
(≥100 kg/mo) must conform to EPA regulations governing
storage, transportation, treatment, and waste disposal.
Incineration in the presence of a flammable solvent.
A flue gas scrubber is recommended as well.
メチルイソシアナート 上流と下流の製品情報
原材料
カルシウムオキシド
メチルアミン
メチルカルバミド酸クロリド
ベンジン
カリウムシアナート
シアン酸ナトリウム
o-ジクロロベンゼン
ジメチル硫酸
1,2,4-Dithiazolidine-3,5-dione, 4-methyl-
Carbamic acid, N-methyl-N-(trimethylsilyl)-, trimethylsilyl ester
Silanamine, 1,1,1-trimethyl-N-(methylcarbonimidoyl)-
アセトヒドロキサム酸
N-メチルベンゼンスルホンアミド
3-メチル-1,1-ジフェニル尿素
準備製品