1,4-Dichlorobenzene Chemical Properties
- Melting point:
- 52-54 °C(lit.)
- Boiling point:
- 174 °C
- 1.241 g/mL at 25 °C(lit.)
- vapor density
- 5.07 (vs air)
- vapor pressure
- 1.03 mm Hg ( 25 °C)
- refractive index
- Flash point:
- 150 °F
- storage temp.
- Specific Gravity
- 7 (0.06g/l, H2O, 20℃)
- explosive limit
- Water Solubility
- Henry's Law Constant
- 1.88 at 25 °C (continuous flow sparger, Sproule et al., 1991)
- Exposure limits
- TLV-TWA 75 ppm (～450 mg/m3) (MSHA, OSHA, and NIOSH); IDLH 1000 ppm (NIOSH).
- Stable. Combustible. Incompatible with strong oxidizing agents, aluminium and its alloys, some plastics.
- CAS DataBase Reference
- 106-46-7(CAS DataBase Reference)
- NIST Chemistry Reference
- Benzene, 1,4-dichloro-(106-46-7)
- EPA Substance Registry System
- p-Dichlorobenzene (106-46-7)
- Hazard Codes
- Risk Statements
- Safety Statements
- UN 3077 9/PG 3
- WGK Germany
- Autoignition Temperature
- >500 °C
- HS Code
- Hazardous Substances Data
- 106-46-7(Hazardous Substances Data)
- LD50 in male, female rats (mg/kg): 3863, 3790 orally; >6000, >6000 dermally (Gaines, Linder)
1,4-Dichlorobenzene Usage And Synthesis
colourless or white crystals
There are three isomeric forms of dichlorobenzene (DCB): m-DCB is a flammable liquid and vapor.
Colorless to white crystals with a penetrating, sweet, mothball or almond-like odor. At 40 °C, the average odor threshold concentration and the lowest concentration at which an odor was detected were 18 and 4.5 μg/L, respectively. Similarly, at 25 °C, the average taste threshold concentration and the lowest concentration at which a taste was detected were 32 and 11 μg/L, respectively (Young et al., 1996). A detection odor threshold concentration of 73 μg/m3 (121 ppbv) was reported by Punter (1983).
The compound 1,4-dichlorobenzene is most commonly referred to as para-DCB or p-DCB. It is widely used as a moth killer, in space deodorizers, and in the production of polyphenylene sulfide. It is also used in the manufacture of certain resins, in the pharmaceutical industry, and as a general insecticide in farming. At room temperature, 1,4- dichlorobenzene is a white or colorless crystalline solid with a characteristic penetrating odor. When exposed to air, it is slowly transformed from its solid state into a vapor; the released vapor then acts as a deodorizer and insect killer. It is practically insoluble in water and is soluble in alcohol, acetone, ether, chloroform, carbon disulfide, and benzene. Its chemical formula is C6H4Cl2.
There is limited evidence that 1,4-dichlorobenzene can damage a developing fetus. Exposure can damage the lungs, liver, kidneys, and blood cells, causing anemia; it can also cause swelling of the eyes, hands, and feet. It can damage the nervous system, causing weakness, trembling, and numbness in the arms and legs. It may cause a skin allergy, which when developed can cause itching and a skin rash. Higher levels of the chemical in air, such as the levels that are sometimes associated with industrial exposure, can cause headaches, nausea, clumsiness, slurred speech, and dizziness. Levels that would result in death would be associated with an odor so intense that it would be very unpleasant, if not intolerable, and would serve as a danger warning. In industrial situations, workers exposed to 1,4- dichlorobenzene at high levels are usually directed to wear respirators. Workers involved in the production of the chemical may be exposed to concentrations significantly higher than those encountered by the general population. High exposure levels may result from some consumer products of moth repellents and room deodorizers. Approximately 95% of the environmental release of 1,4- dichlorobenzene occurs during its use, rather than during its manufacture or processing.
1,4-Dichlorobenzene is used as a fumigantand as an insecticide.
Insecticidal fumigant. For domestic use against clothes moths; as space deodorant in room deodorizers, toilet bowl blocks and diaper pail deodorizers. Intermediate in production of plastics for electronic components.
ChEBI: A dichlorobenzene carrying chloro groups at positions 1 and 4.
dichlorobenzene: Any one of threeisomeric liquid aromatic compounds,C6H4Cl2. 1,2-Dichlorobenzene (b.p.179°C) and 1,4-dichlorobenzene (b.p.174°C) are made by chlorinatingbenzene with an iron catalyst andseparating the mixed isomers byfractional distillation; 1,3-dichlorobenzene(b.p. 172°C) is made fromone of the other two by catalytic isomerization.The 1,2 isomer is used asan insecticide and in making dyes;the 1,4 compound is employed as adeodorant and moth repellent.
A white colored liquid with the odor of moth balls. Denser than water and insoluble in water. Flash point below 200°F. Used as a moth repellent, to make other chemicals, as a fumigant, and for many other uses.
Air & Water Reactions
Insoluble in water.
1,4-Dichlorobenzene is incompatible with oxidizing agents. 1,4-Dichlorobenzene is also incompatible with aluminum and its alloys. 1,4-Dichlorobenzene liquefies when mixed with camphor, phenol and salol. 1,4-Dichlorobenzene will attack some forms of plastics, rubber and coatings. .
INHALATION: irritation of upper respiratory tract; over- exposure may cause depression and injury to liver and kidney. EYE CONTACT: pain and mild irritation.
Toxic symptoms are headache, weakness,dizziness, nausea, vomiting, diarrhea, loss ofweight, and injury to liver and kidney. Thesesymptoms occur from repeated inhalationof high concentrations of vapors or fromingestion. The vapors are an irritant to theeyes, throat, and skin. Chronic exposure maycause jaundice and cirrhosis. The oral LD50value in mice is in the range 3000 mg/kg.The fatal oral dose in humans is estimated tobe 40–50 g. Carcinogenic studies on animalshave not produced adequate evidence of anycancer-causing action.
Special Hazards of Combustion Products: Vapors are irritating. Toxic chlorine, hydrogen chloride, and phosgene gases may be generated in fires.
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.
Insecticide, Rodenticide, Fungicide: p-Dichlorbenzene is used primarily as an air deodorant, as moth balls, 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 byproducts during the production of monochlorobenzene. 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. The para-isomer of dichlorobenzene is the isomer most prominently used in agriculture. Not listed for use in EU countries.
DowTHERM®; EVOLA; PARACIDE®; PARA CRYSTALS®; PARADI®; PARADOW®; PARAMOTH®; PARANUGGETS®; PARAZENE®; PERSIA-PERAZOL®; SANTOCHLOR®; Mixed isomers: DILATIN DBI®; MOTTENSCHUTZMITTEL EVAU P®; MOTT-EX®; TOTAMOTT®
Confirmed carcinogen with experimental carcinogenic data. An experimental teratogen. A human poison by an unspecified route. Moderately toxic to humans by ingestion. Moderately toxic experimentally by ingestion, subcutaneous, and intraperitoneal routes. Other experimental reproductive effects. Human systemic effects by ingestion: unspecified changes in the eyes, lungs, thorax and respiration, and decreased motihty or constipation. Can cause liver injury in humans. A human eye irritant. Mutation data reported. A fumigant. Flammable liquid when exposed to heat, flame, or oxidizers. Dangerous; can react vigorously with oxidizing materials. To fight fire, use water, foam, CO2, dry chemical. When heated to decomposition it emits toxic fumes of Cl-. See also 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
1,4-Dichlorobenzene is reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity from studies in experimental animals.
Biological. In activated sludge, <0.1% degraded (mineralized) to carbon dioxide after 5 d
(Freitag et al., 1985). When 1,4-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, 55, 61, 34, and 16% losses were observed after 7, 14, 21, and 28-d incubation periods,
respectively. At a concentration of 10 mg/L, only 37, 54, 29, and 0% losses were observed after 7,
14, 21, and 28-d incubation periods, respectively (Tabak et al., 1981).
Surface Water. Estimated half-lives of 1,4-dichlorobenzene (1.5 μg/L) from an experimental marine mesocosm during the spring (8–16 °C), summer (20–22 °C), and winter (3–7 °C) were 18, 10, and 13 d, respectively (Wakeham et al., 1983).
Groundwater. Nielsen et al. (1996) studied the degradation of 1,4-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 1,4-dichlorobenzene concentrations with time. The experimentally determined first-order biodegradation rate constant and corresponding half-life following a 22-d lag phase were 0.05/d and 13.86 d, respectively.
Under anaerobic conditions, 1,4-dichlorobenzene in a plume of contaminated groundwater was found to be very persistent (Barber, 1988).
Photolytic. Under artificial sunlight, river water containing 2 to 5 ppm of 1,4-dichlorobenzene photodegraded to chlorophenol and phenol (Mansour et al., 1989). A carbon dioxide yield of 5.1% was achieved when 1,4-dichlorobenzene adsorbed on silica gel was irradiated with light (λ >290 nm) for 17 h (Freitag et al., 1985). Irradiation of 1,4-dichlorophenol in air containing nitrogen oxides gave 2,5-dichlorophenol (major product), 2,5-dichloronitrobenzene, 2,5-dichlorophenol, and 2,5-dichloro-4-nitrophenol (Nojima and Kanno, 1980). The sunlight irradiation of 1,4- dichlorobenzene (20 g) in a 100-mL borosilicate glass-stoppered Erlenmeyer flask for 56 d yielded 1,860 ppm 2′,4,5′-trichlorobiphenyl (Uyeta et al., 1976).
Chemical/Physical. Anticipated products from the reaction of 1,4-dichlorobenzene with ozone or OH radicals in the atmosphere are chlorinated phenols, ring cleavage products, and nitro compounds (Cupitt, 1980).
1,4-Dichlorobenzene undergoes degradation by the Xanthobacter flavus 14p1 isolated from river sludge by selective enrichment with 1,4-dichlorobenzene, resulting in the degradation products 3,6-dichloro-cis- 1,2-dihydroxycyclohexa-3,5-diene and 3,6- dichlorocatechol. 2,5-Dichloromuconic acid and 2- chloromaleylacetic acid, as well as the decarboxylation product 2-chloroacetoacrylic acid, are identified after enzymatic conversion of 3,6-dichlorocatechol.
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
o-Dichlorobenzene is a common impurity. The p-isomer has been purified by steam distillation, crystallisation from EtOH or boiling MeOH, air-dried and dried in the dark under vacuum. It has also been purified by zone refining. [Beilstein 5 IV 658.]
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
- 2,4-Dichlorobenzyl chloride
- 3,4-Dichlorobenzoic acid
- 2,4-Dichlorobenzoic acid
- BIS(2,4,5-TRICHLOROPHENYL) DISULFIDE
- CARBONIC ACID TERT-BUTYL 2,4,5-TRICHLOROPHENYL ESTER
- 400-666-7788 010-82848833-
- 400-660-8290 21-61259100-
- 021-67121386 / 800-988-0390