Hexachlorobenzene(118-74-1), or perchlorobenzene, is a chlorocarbon with the molecular formula C₆Cl₆. It is a white crystalline solid that has negligible solubility in water. It is soluble in diethyl ether, benzene, ethanol and chloroform. Its vapour pressure is 1.09×10^-5 mmHg (1.45 mPa) at 20 °C. Its flash point is 242 °C and it sublimes at 322 °C.
IUPAC Name: 1,2,3,4,5,6-hexachlorobenzene
Molecular formula: C₆Cl₆
Molar mass: 284.80 g/mol
Density: 2.04 g/cm³
Melting point: 231 °C
Boiling point: 323-326 °C
Other names: Perchlorobenzene; HCB 
The Structure of Hexachlorobenzene(118-74-1):

Hexachlorobenzene(118-74-1) is a fungicide formerly used as a seed treatment, especially on wheat to control the fungal disease bunt. It has been banned globally under the Stockholm Convention on persistent organic pollutants.

NTP 10th Report on Carcinogens. IARC Cancer Review: Group 2B IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 7 , 1987,p. 219.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) ; Animal Sufficient Evidence IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 20 , 1979,p. 155.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) ; Human Limited Evidence IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 20 , 1979,p. 155.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) . Community Right-To-Know List. Reported in EPA TSCA Inventory. EPA Genetic Toxicology Program.

Confirmed carcinogen with experimental carcinogenic, neoplastigenic, and teratogenic data. A human poison by an unspecified route. Experimental reproductive effects. Mildly toxic experimentally by inhalation. Mutation data reported. A fungicide. Combustible when exposed to heat or flame. Violent reaction with dimethylformamide. To fight fire, use CO₂, dry chemical. When heated to decomposition it emits highly toxic fumes of Cl⁻. See also CHLORINATED HYDROCARBONS, AROMATIC.
Hazard Codes: T,N,Xn,Xi,F
Risk Statements: 45-48/25-50/53-67-65-62-51/53-48/20-38-11-39/23/24/25-23/24/25-66-36/38
45:  May cause cancer 
48/25:  Toxic: danger of serious damage to health by prolonged exposure if swallowed 
50/53:  Very Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment 
67:  Vapors may cause drowsiness and dizziness 
65:  Harmful: May cause lung damage if swallowed 
62:  Possible risk of impaired fertility 
51/53:  Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment 
48/20:  Harmful: danger of serious damage to health by prolonged exposure through inhalation 
38:  Irritating to the skin 
11:  Highly Flammable 
39/23/24/25:  Toxic: danger of very serious irreversible effects through inhalation, in contact with skin and if swallowed 
23/24/25:  Toxic by inhalation, in contact with skin and if swallowed 
66:  Repeated exposure may cause skin dryness or cracking 
36/38:  Irritating to eyes and skin 
Safety Statements: 53-45-60-61-62-36/37-33-29-16-9-26
53:  Avoid exposure - obtain special instruction before use 
45:  In case of accident or if you feel unwell, seek medical advice immediately (show label where possible) 
60:  This material and/or its container must be disposed of as hazardous waste 
61:  Avoid release to the environment. Refer to special instructions safety data sheet 
62:  If swallowed, do not induce vomiting: seek medical advice immediately and show this container or label 
36/37:  Wear suitable protective clothing and gloves 
33:  Take precautionary measures against static discharges 
29:  Do not empty into drains 
16:  Keep away from sources of ignition - No smoking 
9:  Keep container in a well-ventilated place 
26:  In case of contact with eyes, rinse immediately with plenty of water and seek medical advice 
RIDADR: UN 2729 6.1/PG 3
WGK Germany: 3
RTECS: DA2975000
HazardClass: 6.1(b)
PackingGroup: III

ACGIH TLV: TWA 0.002 (skin); Animal Carcinogen
DFG MAK: Not Classifiable as a Human Carcinogen; BAT: 15 μg/dL in plasma/serum
DOT Classification:  6.1; Label: KEEP AWAY FROM FOOD