ヘキサクロロベンゼン

解説

ヘキサクロロベンゼン．塩化アルミニウムと塩化硫黄とを触媒にして，クロロベンゼンを塩化スルフリルで塩素化すると得られる．針状晶．融点229 ℃，沸点326 ℃．昇華性がある．有機溶媒に可溶，冷エタノールに微溶，水に不溶．毒性は比較的低いが，長期間さらされると関節炎，甲状腺肥大などを起こす．有機合成用試薬，農薬(殺菌剤)に用いられる．

用途

殺菌剤、防かび剤、防汚剤、合成中間体。EUでは使われておらず塩ビに含まれる非意図的副生成物。日本では71年製造?使用?輸入禁止

農薬用途

殺菌剤

説明

Hexachlorobenzene is a white crystalline solid. This compound does not occur naturally. It is formed as a by-product during the manufacture of chemicals used as solvents (substances used to dissolve other substances), other chlorine-containing compounds, and pesticides. Small amounts of hexachlorobenzene can also be produced during combustion processes such as burning of city wastes. It may also be produced as a by-product in waste streams of chlor-alkali and wood-preserving plants. Hexachlorobenzene was widely used as a pesticide until 1965. It was also used to make fireworks, ammunition, and synthetic rubber.

化学的特性

Hexachlorobenzene is a solid, crystallizing in nee dles.

使用

Hexachlorobenzene is used as a fungicideand as an intermediate in organic synthesis.

定義

hexachlorobenzene: A colourlesscrystalline compound, C₆Cl₆; m.p.227°C. It is made by the chlorinationof benzene with an iron(III) chloridecatalyst or by treating hexachlorocyclohexanewith chlorine in hexachloroethane.It is used to preservewood and dress seeds, and in themanufacture of hexafluorobenzene.

一般的な説明

A white crystalline substance. Insoluble in water and denser than water. Contact may irritate skin, eyes and mucous membranes. May be toxic by ingestion. Used to make other chemicals.

空気と水の反応

HEXACHLOROBENZENE is sensitive to moisture. Insoluble in water.

反応プロフィール

HEXACHLOROBENZENE reacts violently with dimethylformamide. .

危険性

Possible carcinogen. Toxic by ingestion. Combustible.

健康ハザード

The acute oral and inhalation toxicity ofhexachlorobenzene is low in test animals.Repeated ingestion of this compound mayproduce porphyria hepatica (increased for mation and excretion of porphyrin) causedby disturbances in liver metabolism. The oralLD50 value in rabbits is 2600 mg/kg; theinhalation LC50 value from a single exposureis 1800 mg/m³ (NIOSH 1986). The occupa tional health hazard from inhalation shouldbe very low because of its very low vaporpressure (0.00001 torr).
Hexachlorobenzene causes cancer in ani mals. Oral administration of this compoundfor 18 weeks to 2 years caused tumors inthe liver, kidney, thyroid, and blood in rats,mice, and hamsters. It is a suspected humancarcinogen, evidence of which occurs to alimited extent.

火災危険

Noncombustible solid; very low reactiv ity. Reaction with dimethyl formamide is reported to be violent at temperatures above 65°C (149°F) (NFPA 1997).

職業ばく露

Hexachlorobenzene was used as a fun gicide; an additive for pyrotechnic compositions; and as wood preservative. It was used widely as a pesticide to pro tect seeds of onions and sorghum, wheat, and other grains against fungus until 1965. This material was used to make fireworks; ammunition for military uses; synthetic rubber; as a porosity controller in the manufacture of electrodes; as an intermediate in dye manufacture; in organic synthesis. It is formed as a by-product of making other chemicals; in the waste streams of chloralkali and wood-preserving plants; and when burning municipal waste. Currently, there are no commercial uses of hexachlorobenzene in the United States.

発がん性

Hexachlorobenzene is reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity from studies in experimental animals.

代謝経路

With the incubation of rat liver microsomes, hexachlorobenzene is metabolized to give pentachlorophenol and tetrachlorohydroquinone, and, in addition, a considerable amount of covalent binding to protein is detected (250 pM pentachlorophenol, 17 pM tetrachlorohydroquinone, and 11 pM tetrachlorobenzoquinone covalent binding in an incubation containing 50 μM hexachlorobenzene).

代謝

Sensitized photolysis of HCB at wavelengths greater than 285 nm in acetonitrile/water containing acetone gave dechlorinated products: pentachlorobenzene (78) (71%), 1,2,3,4-tetrachlorobenzene (79) (0.6%), 1,2,3,5-tetrachlorobenzene (80) (2.2%), and 1,2,4,5- tetrachlorobenzene (81) (3.7%). Without acetone, products included pentachlorobenzene (78) (76.8%), 1,2,3,5-tetrachlorobenzene (80) (1.2%), 1,2,4,5- tetrachlorobenzene (81) (1.7%), and 1,2,4-trichlorobenzene (82) (0.2%) (105).
Irradiation of hexachlorobenzene in methanol solution at wavelengths greater than 260 nm gave a mixture of reductively dechlorinated products (pentachlorobenzene and a tetrachlorobenzene, probably 80) and pentachlorobenzyl alcohol 83, and also a tetrachlorodi( hydroxymethyl)benzene (106). A similar product mixture was obtained by exposing a methanolic solution of hexachlorobenzene inmethanol to sunlight outdoors. After 15 days, only 30% of hexachlorobenzene was recovered. Photolysis rates were enhanced by the addition of sensitizers (diphenylamine, tryptophane, and naturally occurring organic substances), but no products were identified.
In an anaerobic sewage sludge, hexachlorobenzene was reductively dechlorinated and the principal product was 1,3,5-trichlorobenzene (84). Pentachlorobenzene, 1,2,3,5- tetrachlorobenzene, and dichlorobenzenes were also identified (107). In activated sludge, 1.5% of hexachlorobenzene was mineralized as carbon dioxide after 5 days.

輸送方法

UN2729 Hexachlorobenzene, Hazard Class: 6.1; Labels: 6.1-Poisonous materials.

純化方法

Crystallise hexachlorobenzene repeatedly from *benzene. Dry it under vacuum over P2O5. [Beilstein 5 H 205, 5 IV 670.]

不和合性

Reacts violently with oxidizers; dimethyl formamide above 65 ℃.

廃棄物の処理

Incineration is most effective @ 1300 ℃ and 0.25 seconds. 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.