1,2-Dichlorobenzene Chemical Properties
- Melting point:
- -15 °C
- Boiling point:
- 179 °C
- 1.306 g/mL at 25 °C(lit.)
- vapor density
- 5.1 (vs air)
- vapor pressure
- 1.2 mm Hg ( 20 °C)
- refractive index
- Flash point:
- 150 °F
- storage temp.
- Clear colorless to very slightly yellow
- Aromatic; characteristic aromatic.
- explosive limit
- Water Solubility
- 0.13 g/L (20 ºC)
- λ: 296 nm Amax: 1.00
λ: 300 nm Amax: 0.30
λ: 305 nm Amax: 0.20
λ: 335 nm Amax: 0.05
λ: 375-400 nm Amax: 0.01
- Henry's Law Constant
- 1.92 at 25 °C (gas stripping-GC, Shiu and Mackay, 1997)
- Exposure limits
- Ceiling 50 ppm (～300 mg/m3) (MSHA, OSHA, and NIOSH); IDLH 1700 ppm (NIOSH).
- Stable, but possibly light sensitive. Combustible. Incompatible with oxidizing agents, aluminium, aluminium alloys. Attacks some rubbers and plastics.
- CAS DataBase Reference
- 95-50-1(CAS DataBase Reference)
- 3 (Vol. Sup 7, 73) 1999
- NIST Chemistry Reference
- Benzene, 1,2-dichloro-(95-50-1)
- EPA Substance Registry System
- o-Dichlorobenzene (95-50-1)
- Hazard Codes
- Risk Statements
- Safety Statements
- UN 1993 3/PG 2
- WGK Germany
- Autoignition Temperature
- 640 °C
- HS Code
- Hazardous Substances Data
- 95-50-1(Hazardous Substances Data)
- LD50 orally in Rabbit: 500 mg/kg LD50 dermal Rabbit > 10000 mg/kg
1,2-Dichlorobenzene Usage And Synthesis
There are three isomeric forms of dichlorobenzene (DCB): m-DCB is a flammable liquid and vapor.
1,2-Dichlorobenzene (DCB, o-Dichlorobenzene, ODB, Orthodichlorobenzene), C6H4Cl2, is a colorless to pale yellow liquid with a pleasant aromatic odor. It is a combustible liquid and can form explosive mixtures with air at or above 151°F. Combustion and thermal decomposition products include hydrogen chloride gas, phosgene and chloro-carbons. Its flammable (explosive) limits are as follows: Lower 2.2%, Upper 9.2%.
Clear, colorless to pale yellow liquid with a pleasant, aromatic, grassy or vegetable-type odor. At 40 °C, the lowest concentration at which an odor was detected was 200 μg/L. At 25 °C, the lowest concentration at which a taste was detected was 200 μg/L (Young et al., 1996). A detection odor threshold concentration of 4.2 mg/m3 (699 ppbv) was reported by Punter (1983).
Organic synthesis (primarily 3,4- dichloroaniline); solvent; insecticide; dye manufacture
1,2-Dichlorobenzene is used as a solvent; asa fumigant; as an insecticide for termites;as a degreasing agent for metals, wool, andleather; and as a heat transfer medium.
Solvent for waxes, gums, resins, tars, rubbers, oils, asphalts; insecticide for termites and locust borers; fumigant; deodorizer; removing sulfur from illuminating gas; as degreasing agent for metals, leather, wool; as ingredient of metal polishes; as heat transfer medium; as intermediate in the manufacture of dyes.
ChEBI: A dichlorobenzene carrying chloro substituents at positions 1 and 2.
Dichlorobenzenes are primarily produced by the chlorination of benzene in the presence of a catalyst (FeCl3 or AlCl3) although there are other possible synthetic routes. The two commercially important isomers are the ortho- and para-dichlorobenzenes.
A clear colorless liquid with a pleasant odor. Denser than water and insoluble in water. Flash point 150°F. Toxic by inhalation and ingestion. Used to make other chemicals, solvents, fumigants and insecticides and for many other uses.
Air & Water Reactions
Insoluble in water.
1,2-Dichlorobenzene is sensitive to prolonged exposure to light. 1,2-Dichlorobenzene can react vigorously with oxidizers. 1,2-Dichlorobenzene is incompatible with aluminum and aluminum alloys. 1,2-Dichlorobenzene attacks some forms of plastics, rubber and coatings. .
Chronic inhalation of mist or vapors may result in damage to lungs, liver, and kidneys. Acute vapor exposure can cause symptoms ranging from coughing to central nervous system depression and transient anesthesia. Irritating to skin, eyes, and mucous membranes. May cause dermatitis.
1,2-Dichlorobenzene exhibits low acute toxi city by inhalation, ingestion, and skin absorp tion. It is more toxic than chlorobenzene.The symptoms are lacrimation, depression ofcentral nervous system, anesthesia, and liverdamage. Lethal concentration in rats for a7-hour exposure period is in the range of800 ppm. The oral LD50 value in rabbits is500 mg/kg. There is no evidence of carcino genicity in animals.
Special Hazards of Combustion Products: Poisonous vapors including hydrogen chloride gas, chlorocarbons, chlorine
Reactivity with Water No reaction; Reactivity with Common Materials: No reaction; Stability During Transport: Stable; Neutralizing Agents for Acids and Caustics: Not pertinent; Polymerization: Not pertinent; Inhibitor of Polymerization: Not pertinent.
Poison by ingestion and intravenous routes. Moderately toxic by inhalation and intraperitoneal routes. An experimental teratogen. Other experimental reproductive effects. An eye, skin, and mucous membrane irritant. Causes liver and hdney injury. Questionable carcinogen. Mutation data reported. A pesticide. Flammable when exposed to heat or flame. Can react vigorously with oxidizing materials. To fight fire, use water, foam, CO2, or dry chemical. Slow reaction with aluminum may lead to explosion during storage in a sealed aluminum container. When heated to decomposition it emits toxic fumes of Cl-. See also CHLOROBENZENE and CHLORINATED HYDROCARBONS, AROMATIC.
The major uses of o-DCB are as a process solvent in the manufacturing of toluene diisocyanate and as an intermediate in the synthesis of dyestuffs, herbicides, and degreasers. p-Dichlorbenzene is used primarily as a moth repellant, a mildew control agent; space deodorant; and in insecticides, which accounts for 90% of the total production of this isomer. Information is not available concerning the production and use of m-DCB. However, it may occur as a contaminant of o-or p-DCB formulations. Both o-and p-isomers are produced almost entirely as by-products during the production of monochlorobenzene
Biological. Pseudomonas sp. isolated from sewage samples produced 3,4-dichloro-cis-1,2-
dihydroxycyclohexa-3,5-diene. Subsequent degradation of this metabolite yielded 3,4-
dichlorocatechol, which underwent ring cleavage to form 2,3-dichloro-cis,cis-muconate, followed
by hydrolysis to form 5-chloromaleylacetic acid (Haigler et al., 1988). When 1,2-dichlorobenzene
was statically incubated in the dark at 25 °C with yeast extract and settled domestic wastewater
inoculum, significant biodegradation with gradual acclimation was followed by a deadaptive
process in subsequent subcultures. At a concentration of 5 mg/L, 45, 66, 48, and 29% losses were
observed after 7, 14, 21, and 28-d incubation periods, respectively. At a concentration of 10 mg/L,
only 20, 59, 32, and 18% losses were observed after 7, 14, 21, and 28-d incubation periods,
respectively (Tabak et al., 1981).
Groundwater. Nielsen et al. (1996) studied the degradation of 1,2-dichlorobenzene in a shallow,glaciofluvial, unconfined sandy aquifer in Jutland, Denmark. As part of the in situ microcosm study, a cylinder that was open at the bottom and screened at the top was installed through a cased borehole approximately 5 m below grade. Five liters of water was aerated with atmospheric air to ensure aerobic conditions were maintained. Groundwater was analyzed weekly for approximately 3 months to determine 1,2-dichlorobenzene concentrations with time. The experimentally determined first-order biodegradation rate constant and corresponding half-life following a 13-d lag phase were 0.06/d and 11.55 d, respectively.
Photolytic. Titanium dioxide suspended in an aqueous solution and irradiated with UV light (λ = 365 nm) converted 1,2-dichlorobenzene to carbon dioxide at a significant rate (Matthews, 1986). The sunlight irradiation of 1,2-dichlorobenzene (20 g) in a 100-mL borosilicate glass-stoppered Erlenmeyer flask for 56 d yielded 2,270 ppm 2,3′,4′-trichlorobiphenyl (Uyeta et al., 1976).
When an aqueous solution containing 1,2-dichlorobenzene (190 μM) and a nonionic surfactant micelle (Brij 58, a polyoxyethylene cetyl ether) was illuminated by a photoreactor equipped with 253.7-nm monochromatic UV lamps, photoisomerization took place yielding 1,3- and 1,4- dichlorobenzene as the principal products. The half-life for this reaction, based on the first-order photodecomposition rate of 1.35 x 10-3/sec, is 8.6 min (Chu and Jafvert, 1994).
Chemical/Physical. Anticipated products from the reaction of 1,2-dichlorobenzene with ozone or OH radicals in the atmosphere are chlorinated phenols, ring cleavage products, and nitro compounds (Cupitt, 1980). Based on an assumed base-mediated 1% disappearance after 16 d at 85 °C and pH 9.70 (pH 11.26 at 25 °C), the hydrolysis half-life was estimated to be >900 yr (Ellington et al., 1988).
m-DCB: UN2810 Toxic liquids, organic, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name Required. United States DOT Regulated Marine Pollutant. UN3077 Environmentally hazardous substances, solis, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous hazardous material, Technical NameRequired. UN3082 Environmentally hazardous substances, liquid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous hazardous material, Technical Name Required
Contaminants may include the p-isomer and trichlorobenzene [Suslick et al. J Am Chem Soc 106 4522 1984]. It should be shaken with conc or fuming H2SO4, washed with water, dried with CaCl2, and distilled from CaH2 or sodium in a glass-packed column. Low conductivity material (ca 10-10 mhos) has been obtained by refluxing with P2O5, fractionally distilling and passing it through a column packed with silica gel or activated alumina: it is stored in a dry-box under N2 or with activated alumina. [Beilstein 5 IV 654.]
For o-DCB and m-DCB: acid fumes, chlorides, strong oxidizers; hot aluminum, or aluminum alloys. For p-DCB: Strong oxidizers; although, incompatibilities for this chemical may also include other materials listed for o-DCB.
Incineration, preferably after mixing with another combustible fuel. Care must be exercised to assure complete combustion to prevent the formation of phosgene. An acid scrubber is necessary to remove the halo acids produced. Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Generators of waste containing this contaminant (≥100 kg/mo) must conform with EPA regulations governing storage, transportation, treatment, and waste disposal
1,2-Dichlorobenzene Preparation Products And Raw materials
- CARBONIC ACID TERT-BUTYL 2,4,5-TRICHLOROPHENYL ESTER
- 2,4-Dichlorobenzyl chloride
- 2,4-Dichlorophenoxyacetic acid
- Dichlorobenzene, 1,4-Dichlorocide,Dichlorobenzene, 1,4-Dichlorocide
- 13852725268 0514-86371145-
- 400-620-6333 021-20337333-801
- 400-666-7788 010-82848833-
- 400-660-8290 21-61259100-