1,4-Dichlorobenzene

Hazardous Air Pollutants (HAPs)

Carcinogens

Volatile Organic Compound (VOC) and(or) Waste-water effluent contaminant

Pesticide -> EPA IRIS

Rodenticides

Active substance -> EU Pesticides database: Not approved

Pesticides -> Fumigants

log Kow = 3.44

3.44

3.37

3.48

Distinctive aromatic odor ... becomes very strong at concentrations between 30 and 60 ppm

Strong penetrating odor

Mothball-like odor

1.458 at 68 °F (USCG, 1999) - Denser than water; will sink

1.2475 g/cu cm at 25 °C

Density: 1.4581 at 20.5 °C/4 °C

1.2 g/cm³

Relative density of the vapour/air-mixture at 20 °C (air = 1): 1.01

1.458

0.839 mPa.s at 55 °C; 0.668 mPa.s at 79 °C

0.73 mPa*s at 70 °C

White crystals

Volatile crystals

White crystals or leaflets

Colorless or white crystalline solid

less than 1 mg/mL at 73 °F (NTP, 1992)

In water, 81.3 mg/L at 25 °C

Practically insoluble in water

Soluble in chloroform, carbon disulfide, benzene, ether, alcohol

Miscible with ethanol, acetone, benzene; soluble in ethyl ether, chloroform

0.0813 mg/mL at 25 °C

150 °F (NTP, 1992)

66.0 °C (150.8 °F) - closed cup

150 °F (66 °C) (closed cup)

66 °C c.c.

150 °F

150 °F

345 °F at 760 mmHg (NTP, 1992)

173.9 °C

174 °C

345 °F

174 °C @760 [mm Hg]

345 °F

Warning

H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]

P203, P264+P265, P273, P280, P305+P351+P338, P318, P337+P317, P391, P405, and P501 (click each P-code to see the statement)

Warning

H319 (100%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]

P203, P264+P265, P273, P280, P305+P351+P338, P318, P337+P317, P391, P405, and P501 (click each P-code to see the statement)

Chemical: Benzene, 1,4-dichloro-

Hazard Traits - Carcinogenicity; Dermatotoxicity; Hepatotoxicity and Digestive System Toxicity; Nephrotoxicity and Other Toxicity to the Urinary System; Neurotoxicity; Ocular Toxicity; Reproductive Toxicity; Respiratory Toxicity

Benzene, 1,4-dichloro- is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Benzene, 1,4-dichloro- are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)

T - indicates a substance that is the subject of a final TSCA section 4 test rule.

2004/129/EC

Status: Active Update: 15-09-2022 https://echa.europa.eu/registration-dossier/-/registered-dossier/14821

Special Hazards of Combustion Products: Vapors are irritating. Toxic chlorine, hydrogen chloride, and phosgene gases may be generated in fires. (USCG, 1999)

Combustible. Gives off irritating or toxic fumes (or gases) in a fire. Above 66 °C explosive vapour/air mixtures may be formed. Finely dispersed particles form explosive mixtures in air.

The primary exposure to 1,4-dichlorobenzene is from breathing contaminated indoor air. Acute (short- term) exposure to 1,4-dichlorobenzene, via inhalation in humans, results in irritation of the skin, throat, and eyes. Chronic (long-term) 1,4-dichlorobenzene inhalation exposure in humans results in effects on the liver, skin, and central nervous system (CNS). No information is available on the reproductive, developmental, or carcinogenic effects of 1,4-dichlorobenzene in humans. A National Toxicology Program (NTP) study reported that 1,4-dichlorobenzene caused kidney tumors in male rats and liver tumors in both sexes of mice by gavage (experimentally placing the chemical in their stomachs). EPA has classified 1,4- dichlorobenzene as a Group C, possible human carcinogen.

After daily doses of 500 mg/kg, rats develop focal hepatic necrosis. TLV Basis: eye irritation and kidney damage; Humans report eye irritation at 17 ppm and higher. Renal toxicity is observed in animal experiments at 25 ppm and higher. Hemolytic anemia, methemoglobinuria, and jaundice have been reported after ingestion. [ACGIH] Experimental animals suffer CNS depression and liver and kidney damage after high-dose inhalation studies. [CHEMINFO] Suspected germ cell mutagen (3B); [MAK]

USEPA/Office of Prevention, Pesticides and Toxic Substances; Reregistration Eligibility Decision Document - Para-dichlorobenzene, Revised December 2008 EPA 738-R-07-010 (December 2008). The RED summarizes the risk assessment conclusions and outlines any risk reduction measures necessary for the pesticide to continue to be registered in the USA.[Available from, as of March 23, 2018: http://www.epa.gov/pesticides/reregistration/status.htm]

USEPA; Ambient Water Quality Criteria Doc: Dichlorobenzenes (1980) EPA 440/5-80-039

Hawkins DR et al, Xenobiotica; 10 (2): 81 (1980). Discusses distribution, excretion, and biotransformation of p-dichloro-(14)C-benzene in rats.

USEPA; Health Assessment Document: Chlorinated Benzenes (1985) EPA-600/8-84-015F

For more Special Reports (Complete) data for 1,4-Dichlorobenzene (17 total), please visit the HSDB record page.

U072; As stipulated in 40 CFR 261.33, when 1,4-dichlorobenzene, as a commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or a manufacturing chemical intermediate, becomes a waste, it must be managed according to Federal and/or State hazardous waste regulations. Also defined as a hazardous waste is any residue, contaminated soil, water, or other debris resulting from the cleanup of a spill, into water or on dry land, of this waste. Generators of small quantities of this waste may qualify for partial exclusion from hazardous waste regulations (40 CFR 261.5).

D027; A solid waste containing 1,4-dichlorobenzene may or may not become characterized as a hazardous waste when subjected to the Toxicity Characteristic Leaching Procedure listed in 40 CFR 261.24, and if so characterized, must be managed as a hazardous waste.

Section 8(a) of TSCA requires manufacturers of this chemical substance to report preliminary assessment information concerned with production, exposure, and use to EPA as cited in the preamble in 51 FR 41329. Effective date 8/4/95; Reporting date 10/3/95.

Pursuant to section 8(d) of TSCA, EPA promulgated a model Health and Safety Data Reporting Rule. The section 8(d) model rule requires manufacturers, importers, and processors of listed chemical substances and mixtures to submit to EPA copies and lists of unpublished health and safety studies. 1,4-Dichlorobenzene is included on this list. Effective date 10/4/82; Sunset date 10/4/92.

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]:

Use water spray, powder, foam, carbon dioxide. In case of fire: keep drums, etc., cool by spraying with water.

Fresh air, rest. Refer for medical attention.

Remove contaminated clothes. Rinse and then wash skin with water and soap.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Give one or two glasses of water to drink. Refer for medical attention .

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

(General first aid procedures)

Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.

Advice for firefighters: Wear self-contained breathing apparatus for firefighting if necessary.

Approach fire from upwind to avoid hazardous vapors and toxic decomposition products. Use water spray, dry chemical, foam, or carbon dioxide. Use water spray to keep fire-exposed containers cool. Extinguish fire using agent suitable for surrounding fire. /o-Dichlorobenzene/

Water may be used to blanket fire.

If material on fire or involved in fire: Extinguish fire using agent suitable for type of surrounding fire (Material itself does not burn or burns with difficulty.).

Keep container tightly closed in a dry and well-ventilated place. Storage class (TRGS 510): 13: Non Combustible Solids.

Store in cool, dry, well-ventilated location. Separate from oxidizing materials. /o-Dichlorobenzene/

Store in a cool, dry, well-ventilated area between 32 °F and 80 °F. Storage below 80 °F will cause crystals to turn white; storage above 80 °F will cause crystals to fuse and cake. Short-term exposure to extremely high temperatures, above 80 °F, can rapidly cause caking. Inspection of containers should be made within ten days of receipt to determine whether fusing or caking has occurred in transit. Store only in closed, properly labeled containers. /99.9% Paradichlorobenzene/

Safe Storage of Pesticides. Always store pesticides in their original containers, complete with labels that list ingredients, directions for use, and first aid steps in case of accidental poisoning. Never store pesticides in cabinets with or near food, animal feed, or medical supplies. Do not store pesticides in places where flooding is possible or in places where they might spill or leak into wells, drains, ground water, or surface water.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Avoid dust formation. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas. Avoid breathing dust. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoided. Methods and materials for containment and cleaning up: Pick up and arrange disposal without creating dust. Sweep up and shovel. Keep in suitable, closed containers for disposal.

ENVIRONMENTAL HAZARDS: Do not discharge effluent containing this product into lakes, streams, ponds, estuaries, oceans or other waters unless in accordance with the requirements of a National Pollutant Discharge Elimination System (NPDES) permit and the permitting authority has been notified in writing prior to discharge. Do not discharge effluent containing this product to sewer systems without previously notifying the local sewage treatment plant authority. For guidance contact your State Water Board or Regional Office of the EPA.

Environmental considerations: Land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. Cover solids with a plastic sheet to prevent dissolving in rain or fire fighting water. /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be sealed with an impermeable flexible membrane liner./

Environmental considerations: Water spill: Use natural deep water pockets, excavated lagoons, or sand bag barriers to trap material at bottom. If dissolved, in region of 10 ppm or greater concentration, apply activated carbon at ten times the spilled amount. Remove trapped material with suction hoses. Use mechanical dredges or lifts to remove immobilized masses of pollutants and precipitates.

For more Cleanup Methods (Complete) data for 1,4-Dichlorobenzene (6 total), please visit the HSDB record page.

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number U072 and D027, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.

Product: Offer surplus and non-recyclable solutions to a licensed disposal company. Contact a licensed professional waste disposal service to dispose of this material. Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber; Contaminated packaging: Dispose of as unused product.

SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.

p-Dichlorobenzene may be disposed of: 1) by making packages of p-dichlorobenzene in paper or other flammable material and burning in a suitable combustion chamber equipped with an appropriate effluent gas cleaning device. 2) By dissolving p-dichlorobenzene in a flammable solvent (such as alcohol) and atomizing in a suitable combustion chamber equipped with an appropriate effluent gas cleaning device. Recommendable method: Incineration.

For more Disposal Methods (Complete) data for 1,4-Dichlorobenzene (13 total), please visit the HSDB record page.

Personal protection: filter respirator for organic gases and particulates adapted to the airborne concentration of the substance. Do NOT let this chemical enter the environment. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Avoid dust formation. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas. Avoid breathing dust. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoided.

Precautions for safe handling: Avoid contact with skin and eyes. Avoid formation of dust and aerosols. Provide appropriate exhaust ventilation at places where dust is formed.

Appropriate engineering controls: Handle in accordance with good industrial hygiene and safety practice. Wash hands before breaks and at the end of workday.

Gloves must be inspected prior to use. Use proper glove removal technique (without touching glove's outer surface) to avoid skin contact with this product. Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. Wash and dry hands.

For more Preventive Measures (Complete) data for 1,4-Dichlorobenzene (18 total), please visit the HSDB record page.

Dichlorobenzene isomers were detected in human blood samples taken from residents of Love Canal, NY at concentrations of 1-68 ng/L(1). Combined 1,3-, 1,4-dichlorobenzene was detected in the personal air of Los Angeles, CA residents at concentrations of 12 and 18 ug/cu m and residents of Contra Costa, CA at a concentration of 5.5 ug/cu m(2). Combined 1,3-, 1,4-dichlorobenzene was detected in the breath of Los Angeles, CA residents at concentrations of 3.5 and 2.8 ug/cu m and residents of Contra Costa, CA at a concentration of 2.5 ug/cu m(2). 1,4-Dichlorobenzene was detected as part of the Minnesota Children's Pesticide Exposure Study. 96% of 73 personal samples from a subset of screened households were above the detection limit of 0.2 ug/cu; the mean concentration was 1.4 ug/cu m. Sampling was conducted between May and September 1997(3). A median personal concentration of 0.54 ug/cu m was reported for non-smoking teachers and non-manufacturing office workers as part of the Boston Exposure Assessment in Microenvironments (BEAM) study(4). 1,4-Dichlorobenzene was identified, not quantified, in human adipose tissue in the US(5). 1,4-Dichlorobenzene was detected in human adipose tissue at a concentration of 146 ug/kg(6). 1,4-Dichlorobenzene was measured in adipose tissue composite samples during the National Human Adipose Tissue Survey (NHATS) at an average concentration in the north central, northeastern, southern, and western United States of 98.1, 77.4, 126, and 35.7 ng/g, respectively(7). Age group concentrations for 0-14, 15-44, and 45+ yr were 101, 66.2, and 120 ng/g, respectively(7). A large study in Canada reported that m-/p-dichlorobenzene (combined) was identified, not quantified, in 86% of 210 breast milk samples(7). A mean blood/air distribution coefficient of 122 was reported in samples from 364 adults (aged 20-59) conducted in 1999-2000 as part of the National Health and Nutritional Examination Survey (NHANES)(8). Serum levels of 1,4-dichlorobenzene was 5.1 ng/mL (25.4 ng/mL max) in 7 of 18 patients with sick building syndrome; control concentrations were 16.8 mean and 171 ng/mL, max(9).

Moth repellent para-dichlorobenzene was detected in human adipose tissue and blood as pollutant together with polychlorinated biphenyls.

... In a previous study of selected children in AR, /it was found/ that 96% of the children had detectable urinary concentration of 2,5-dichlorophenol, the metabolite of p-dichlorobenzene. In the current study in a sample of 1,000 adults who lived throughout the USA, 98% had detectable levels of p-dichlorobenzene in their blood. Urinary 2,5-dichlorophenol concentration ranged up to 8,700 ug/L (median and mean concentration of 30 ug/L and 200 ug/L, respectively). p-Dichlorobenzene blood concentration ranged up to 49 ug/L, with median and mean concentration of 0.33 ug/L and 2.1 ug/L, respectively). The Pearson correlation coefficient for 2,5-dichlorophenol in urine and p-dichlorobenzene in blood was 0.82 (p<0.0001), thus demonstrating a strong association between these exposure measurements. Neither age nor gender was related to urinary 2,5-dichlorophenol or blood p-dichlorobenzene concentration (p>0.40). ...

Administer charcoal as a slurry (240 mL water/30 g charcoal). Following inhalation, move patient to fresh air. Monitor for respiratory distress. If cough or difficulty breathing develops, evaluate for respiratory tract irritation, bronchitis, or pneumonitis. Administer oxygen and assist ventilation as required. Treat bronchospasm with inhaled beta2 agonist and oral or parenteral corticosteroids. After eye exposure, irrigate exposed eyes with copious amounts of room temperature water for at least 15 minutes. If the exposure occurs through dermal contact, remove contaminated clothing and wash exposed area thoroughly with soap and water. In any case, a physician may need to examine the area if irritation or pain persists. (T36)

In a model of liver carcinogenesis, groups of 12 (vehicle control) or 18 male Fischer 344 rats, 10 weeks of age, received a single intraperitoneal injection of either 200 mg/kg bw N-nitrosodiethylamine (NDEA) dissolved in 0.9% saline or saline alone. Two weeks after the NDEA or saline injection, para-dichlorobenzene (purity unspecified) was administered by gavage at doses of 0.1 or 0.4 mmol/kg bw/day in corn oil for 6 weeks; control groups received only corn oil or NDEA in corn oil. One week after the start of para-dichlorobenzene treatment (i.e. week 3), all animals underwent a partial hepatectomy. The study was terminated at the end of week 8. Hepatic foci were identified by immunohistochemical staining for the placental form of glutathione S-transferase. The incidence of hepatic foci was not increased, and the authors concluded that para-dichlorobenzene is not a liver tumor promoter.

The role of endogenous glutathione in protecting against 1,4-dichlorobenzene induced hepatotoxicity was demonstrated in ddY male mice. Unique oral administration of 1,4-dichlorobenzene (100 to 400 mg/kg) in ddY male mice pre-treated by ip injection with a depletor of glutathione synthesis (buthionine sulfoximine BSO) resulted in a dose-dependent hepatotoxicity (serum ALT activity up to X 100, liver necrosis) but 1,4-dichlorobenzene alone (up to 1,200 mg/kg) resulted in no hepatotoxicity. Administration of GSH monoethylester protected mice from the hepatotoxicity of 1,4- dichlorobenzene in combination with BSO; treatment with cytochrome P450-dependent monooxygenase inhibitors prevented hepatotoxicity of 1,4-dichlorobenzene in combination with BSO: this suggests that a metabolite formed by a cytochrome P450-dependent reaction is responsible for the 1,4-dichlorobenzene hepatotoxicity and that this metabolite is likely detoxified by glutathione in mice since 1,4-dichlorobenzene showed no sign of hepatotoxicity in the absence of BSO. On the other hand, inducers of cytochrome P450-dependent monooxygenase did not increase hepatotoxicity of 1,4-dichlorobenzene in combination with BSO probably because they stimulate not only activating but also detoxicating pathways of 1,4-dichlorobenzene metabolism.

In a research program with Syrian Hamster Embryo (SHE) cells examining the relationship between polyamine metabolism and cell transformation, ...the effect of 1,4-dichlorobenzene in comparison and in combination with 12-O-tetradecanoyl phorbol-13- acetate (TPA) on ornithine decarboxylase (ODC) and soluble 72 kDa proteolytic enzymes /was compared/. In addition, DNA fragmentation, considered to be the result of apoptosis, was measured. Activity of ODC was measured by a radioisotope method, the proteolytic enzyme activity was measured following electrophoresis on polyacrylamide gels in which either casein or gelatine had been incorporated and apoptosis was measured by ELISA as 180-200 bp fragments of DNA labelled with BrdU released into the cytoplasm. TPA 0.1 ug/mL induced ODC within the first 1 hr, the enzyme activity reaching a maximum of about 2.0-fold the untreated level in 5-6 hours before returning towards control levels after 8-10 hours. Treatment with 1,4-dichlorobenzene, 10 ug/mL, for 5 hours had no effect on ODC activity, while simultaneous treatment with TPA and 1,4- dichlorobenzene for 5 hours, or TPA for 5 hours followed by 1,4-dichlorobenzene for 2 hours had little effect (slightly inhibitory) on that observed with TPA alone. In contrast, treatment with 1,4-dichlorobenzene for 1 hour followed by TPA for 5 hours increased the ODC activity by about 2.6-fold. Similar treatment protocols led to a TPA-induced reduction in proteolytic enzyme activity to about 92% after 5 hours of treatment, a slight increase by 1,4-dichlorobenzene alone (105%) or after simultaneous exposure to TPA and 1,4-dichlorobenzene for 5 hours (109%) and a slightly greater increase after sequential treatment was with 1,4-dichlorobenzene for 1 hour followed by TPA for 5 hours (121%). Apoptosis was inhibited 30% by TPA, 1.0 ug/mL, and inhibited 25% by 1,4-dichlorobenzene, 5.0 ug/mL.

Hepatic

Liver, respiratory system, eyes, kidneys, skin

Prolonged exposure to high concentration of 1,4-DCB may cause weakness, dizziness, loss of weight, liver injury. Chronic (months to years) ingestion of 1,4-DCB products can provoque skin blotches and problems with red blood cells, such as anemia. There is an indication that 1,4-DCB can affect the development of the nervous system after birth. 1,4-DCB is possibly a human carcinogen. (L395, T63)

LC50; Species: Lepomis macrochirus (bluegill sunfish); Conditions: /static bioassay/; Concentration: 4.54 mg/L for 24 hr; 4.3 mg/L for 48 hr; 4.25 mg/L for 96 hr

LC50; Species: Poecilia reticulata (Guppy) age 3 months, weight 0.18 g, length 2.6 cm; Conditions: freshwater, renewal, dissolved oxygen 2.3-8.7 mg/L; Concentration: 19.7 umol/L for 96 hr (confidence interval: 14.8-26.4 umol/L) /95% purity/

LC50; Species: Poecilia reticulata (guppy); Concentration: 4.0 ppm for 14 days /Conditions of bioassay not specified/

LC50; Species: Palaemonetes pugio (grass shrimp); Concentration: 129 mg/L for 48 hr; 69 mg/L for 96 hr /Conditions of bioassay not specified/

For more Ecotoxicity Values (Complete) data for 1,4-Dichlorobenzene (46 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values of 273(2) and 390(3) indicate that 1,4-dichlorobenzene is expected to have moderate mobility in soil(SRC). Volatilization of 1,4-dichlorobenzene from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 2.41X10-3 atm-cu m/mole(4). 1,4-Dichlorobenzene is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1.74 mm Hg at 25 °C(5). Utilizing the Japanese MITI test, 0% of the Theoretical BOD was reached in 4 weeks(6) indicating that biodegradation is not an important environmental fate process in soil(SRC).

AQUATIC FATE: Based on a classification scheme(1), Koc values of 273(2) and 290(3) indicate that 1,4-dichlorobenzene is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(4) based upon a Henry's Law constant of 2.41X10-3 atm-cu m/mole(5). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 4 hours and 5 days, respectively(SRC). According to a classification scheme(6), BCF values ranging from 33-720(7-10) suggest the potential for bioconcentration in aquatic organisms is moderate to high(SRC). Utilizing the Japanese MITI test, 0% of the Theoretical BOD was reached in 4 weeks(10) indicating that biodegradation is not an important environmental fate process in water(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 1,4-dichlorobenzene, which has a vapor pressure of 1.7 mm Hg at 25 °C(2), is expected to exist solely in the vapor phase in the ambient atmosphere. Vapor-phase 1,4-dichlorobenzene is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 40 days(SRC), calculated from its rate constant of 3.2X10-13 cu cm/molecule-sec at 25 deg(3). 1,4-Dichlorobenzene does not contain chromophores that absorb at wavelengths >290 nm and, therefore, is not expected to undergo direct photolysis by sunlight(4).

1,4-Dichlorobenzene was identified, not quantified in 69 of 234 table ready foods in the US at an average concentration of 10.7 ppb(1). 1,4-Dichlorobenzene was detected in scrambled eggs at concentrations of 18 and 28 ng/g(2). 1,4-Dichlorobenzene was detected in butter (1.3-2.7 ug/kg), margarine (12.2-14.5 ug/kg), peanut butter(1.2-8.8 ug/kg), flour(7.3 ug/kg) and pastry mix (22 ug/kg)(3). 1,4-Dichlorobenzene was detected at a concentration of 5 ng/g in market meat samples in Yugoslavia(4). 1,4-Dichlorobenzene was detected in a UK supermarket survey of 9 different retail vegetables, being one of the most frequently detected compound at 61% and had one of the highest concentrations at 0.26 ug/kg fresh weight(5). The reported concentrations were: carrots (0.198 (core) and 0.416 (peel) ug/kg); potatoes (0.0224 ug/kg (peel)); cauliflower (0.214 (stem) and 0.529 (flower) ug/kg); lettuce (0.237 (inner) and 0.118 (outer) ug/kg); beans (0.717 (seed) and 0.117 (pod) ug/kg); peas (1.31 ug/kg (seeds)); tomatoes (0.619 ug/kg (peel))(5).

1,4-Dichlorobenzene occurrence in foods following a five-year US study conducted from 1996-2000(1).[Table#1494]

The substance can be absorbed into the body by inhalation and by ingestion.

inhalation, skin absorption, ingestion, skin and/or eye contact

Inhalation (L397) ; oral (L397) ; dermal (L397) ; eye contact (L397)

ENVIRONMENTAL: Concentrations of 5.3 ng/g 1,4-dichlorobenzene were found in market milk samples in Yugoslavia(1). 1,4-Dichlorobenzene was detected at average concentrations of 0.68, 0.44 and 1.64 ng/mL in whole milk, 2% milk, and 1% milk, respectively(2). A large study in Canada reported that m-/p-dichlorobenzene (combined) was identified in 86% of 210 breast milk samples(3); the mean concentration of meta- and para-dichlorobenzenes (combined) in whole breast milk was 6.0 ug/kg, and that in milk fat was 160 ug/kg(4).

U072; As stipulated in 40 CFR 261.33, when 1,4-dichlorobenzene, as a commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or a manufacturing chemical intermediate, becomes a waste, it must be managed according to Federal and/or State hazardous waste regulations. Also defined as a hazardous waste is any residue, contaminated soil, water, or other debris resulting from the cleanup of a spill, into water or on dry land, of this waste. Generators of small quantities of this waste may qualify for partial exclusion from hazardous waste regulations (40 CFR 261.5).

D027; A solid waste containing 1,4-dichlorobenzene may or may not become characterized as a hazardous waste when subjected to the Toxicity Characteristic Leaching Procedure listed in 40 CFR 261.24, and if so characterized, must be managed as a hazardous waste.

Section 8(a) of TSCA requires manufacturers of this chemical substance to report preliminary assessment information concerned with production, exposure, and use to EPA as cited in the preamble in 51 FR 41329. Effective date 8/4/95; Reporting date 10/3/95.

Pursuant to section 8(d) of TSCA, EPA promulgated a model Health and Safety Data Reporting Rule. The section 8(d) model rule requires manufacturers, importers, and processors of listed chemical substances and mixtures to submit to EPA copies and lists of unpublished health and safety studies. 1,4-Dichlorobenzene is included on this list. Effective date 10/4/82; Sunset date 10/4/92.

The Agency has completed its assessment of the human health and ecological risks associated with the use of pesticide products containing para-dichlorobenzene. The Agency has determined that para-dichlorobenzene-containing products are eligible for reregistration provided that label amendments are made as outlined in Chapter V. Appendix A summarizes the uses of para-dichlorobenzene that are eligible for reregistration. Appendix B identifies the generic data requirements that the Agency reviewed as part of its determination of reregistration eligibility of para-dichlorobenzene, and lists the submitted studies that the Agency found acceptable. Based on its evaluation of para-dichlorobenzene, the Agency has determined that products containing para-dichlorobenzene, unless labeled and used as specified in this document, would present risks inconsistent with FIFRA. Accordingly, should a registrant fail to implement any of the risk mitigation measures identified in this document, the Agency will take regulatory action to address the risk concerns from the use of para-dichlorobenzene. If all changes outlined in this document are incorporated into the product labels, then all current risks for paradichlorobenzene will be adequately mitigated for the purposes of this determination under FIFRA.

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their continued use. Under this pesticide reregistration program, EPA examines newer health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether the use of the pesticide does not pose unreasonable risk in accordance to newer safety standards, such as those described in the Food Quality Protection Act of 1996. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA '88 were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern than those on List C, and with List C containing pesticides of greater concern than those on List D. p-Dichlorobenzene is found on List C. Case No: 3058; Pesticide type: Insecticide, fungicide, rodenticide, antimicrobial; Case Status: OPP is reviewing data from the pesticide's producers regarding its human health and/or environmental effects, or OPP is determining the pesticide's eligibility for reregistration and developing the Reregistration Eligibility Decision (RED) document.; Active ingredient (AI): p-Dichlorobenzene; Data Call-in (DCI) Date(s): 10/02/92, 02/07/95; AI Status: The producers of the pesticide has made commitments to conduct the studies and pay the fees required for reregistration, and are meeting those commitments in a timely manner.

This action promulgates standards of performance for equipment leaks of Volatile Organic Compounds (VOC) in the Synthetic Organic Chemical Manufacturing Industry (SOCMI). The intended effect of these standards is to require all newly constructed, modified, and reconstructed SOCMI process units to use the best demonstrated system of continuous emission reduction for equipment leaks of VOC, considering costs, non air quality health and environmental impact and energy requirements. p-Dichlorobenzene is produced, as an intermediate or a final product, by process units covered under this subpart.

Listed as a hazardous air pollutant (HAP) generally known or suspected to cause serious health problems. The Clean Air Act, as amended in 1990, directs EPA to set standards requiring major sources to sharply reduce routine emissions of toxic pollutants. EPA is required to establish and phase in specific performance based standards for all air emission sources that emit one or more of the listed pollutants. 1,4-Dichlorobenzene is included on this list.

Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 100 lb or 45.5 kg. The toll free number of the NRC is (800) 424-8802. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV. D.3.b).

para-Dichlorobenzene is designated as a hazardous substance under section 311(b)(2)(A) of the Federal Water Pollution Control Act and further regulated by the Clean Water Act Amendments of 1977 and 1978. These regulations apply to discharges of this substance. This designation includes any isomers and hydrates, as well as any solutions and mixtures containing this substance.

Toxic pollutant designated pursuant to section 307(a)(1) of the Federal Water Pollution Control Act and is subject to effluent limitations.

(CA) CALIFORNIA 5 ug/L

(MA) MASSACHUSETTS 5 ug/L

(AZ) ARIZONA 75 ug/L

(ME) MAINE 21 ug/L

(MN) MINNESOTA 10 ug/L

Maximum contaminant levels (MCL) for organic contaminants apply to community and non-transient, non-community water systems: para-dichlorobenzene, MCL 0.075 mg/L.

EPA 75 ug/L

Maximum contaminant level goal (MCLG) for organic contaminants: para-dichlorobenzene, MCLG 0.075 mg/L.

EPA 75 ug/L

A novel in vitro system was used to evaluate tissue specific toxicity. This system utilizes precision cut organ slices in dynamic organ culture and is viable for up to 24 hrs. The three isomers of dichlorobenzene were added to liver slices prepared from Sprague Dawley rats or human donors. The precursor dichlorobenzenes were radiolabelled and metabolites were separated by classes (i.e. glucuronides, sulfates and glutathione and cysteine conjugates). Covalent Binding of the dichlorobenzenes was also determined after extensive extraction of the tissue. The total amount of metabolism of the dichlorobenzenes varied depending on the isomer and the type of tissue. For example, the Sprague-Dawley rat liver slices metabolized 1,2-DCB and 1,3-DCB at approximately the same rate while 1,4-DCB was metabolized at a slower rate. This metabolism profile was also seen in the majority of the adult human liver slices. However, the fetal human slices showed that 1,4-DCB was metabolized to a greater extent than 1,3-DCB or 1,2-DCB while 1,3-DCB was metabolized at a faster rate than 1,2-DCB. Our results show that liver slices in organ culture are a suitable system for species comparisons and of structure/activity relationships in xenobiotic metabolism with an emphasis on the fate of reactive intermediates. In addition, this system is suitable for evaluation of hepatotoxic potency.

After ingestion of p-dichlorobenzene, 2,5-dichlorophenol (30%) free and as the glucuronide and sulfate and 2,5-dichloroquinol (6%) were excreted. In humans, 2,5-dichlorophenol was also found in the urine.

After oral administration of para-dichlorobenzene to rats, 2 metabolites detected in blood. Metabolites M-1 and M-2 are 2,5-dichlorophenyl methyl sulfoxide and 2,5-dichlorophenyl methyl sulfone. Concentration of M-1 in blood was higher than M-2 for 12 hr after dosing, but blood level of M-2 was higher thereafter. After oral administration of p-DCB to rats 2,5-dichlorophenol was major metabolite.

Rabbits were fed an oral dose of 0.5 g/kg of p-dichlorobenzene /which was then/ oxidized to 2,5-dichlorophenol (35%); conjugated to form glucuronide (36%) and ethereal sulfate (27%); or excreted as 2,5-dichloroquinol (6%).

For more Metabolism/Metabolites (Complete) data for 1,4-Dichlorobenzene (9 total), please visit the HSDB record page.

1,4-dichlorobenzene has known human metabolites that include 2,5-dichlorophenol.

Substances that increase the risk of NEOPLASMS in humans or animals. Both genotoxic chemicals, which affect DNA directly, and nongenotoxic chemicals, which induce neoplasms by other mechanism, are included.

Pesticides designed to control insects that are harmful to man. The insects may be directly harmful, as those acting as disease vectors, or indirectly harmful, as destroyers of crops, food products, or textile fabrics.

The material is apparently well absorbed by the gastrointestinal tract and from lung but not appreciably through skin.

Moth repellent para-dichlorobenzene was detected in human adipose tissue and blood as pollutant together with polychlorinated biphenyls.

Absorption of 1,4-dichlorobenzene through the gastrointestinal tract is rapid. Oral doses of 200 or 800 mg/kg to male Wistar rats appeared in the blood and adipose, kidney, liver, lung, heart, and brain tissue within 30 minutes.

The dichlorobenzenes may be absorbed through the lungs, gastrointestinal tract, and the intact skin. Relatively low water solubility and high lipid solubility favor their penetration of most membranes by diffusion, including pulmonary and GI epithelia, the brain, hepatic parenchyma, renal tubules, and the placenta. /Dichlorobenzenes/

For more Absorption, Distribution and Excretion (Complete) data for 1,4-Dichlorobenzene (14 total), please visit the HSDB record page.

1,4-Dichlorobenzene is used mainly as a fumigant for the control of moths, molds, and mildews, and as a space deodorant for toilets and refuse containers.

Used as an insecticide and fumigant; [ACGIH] Used as a deodorizer for toilets and garbage cans; Also used as a moth repellent and chemical intermediate; [CHEMINFO]

Farming (Pesticides) [Category: Industry]

For 1,4-dichlorobenzene (USEPA/OPP Pesticide Code: 061501) ACTIVE products with label matches. /SRP: Registered for use in the U.S. but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./

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.

Para-Dichlorobenzene is limited to indoor use only. It is used as a moth and beetle repellant in products which are applied to commercial and residential use sites such as closets and storage containers, and to repel lice and mites from bird cages. It is also used in empty bee supers (stored indoors), to repel wax moths. When formulated into varpal rope, it is used in attics to repel snakes, mice, rats, squirrels, and bats.

(1972) 4.5X10+9 GRAMS

CHEMICAL PROFILE: p-Dichlorobenzene. Exports: 2002: 12 million pounds; 2003: 11 million pounds

(1978) 1.09X10+7 g

CHEMICAL PROFILE: p-Dichlorobenzene. Imports: 2002: 10 million pounds; 2003: 20 million pounds

2023: 10,000,000 - <50,000,000 lb

(1972) 3.5X10+10 GRAMS

(1975) 2.08X10+10 GRAMS

(1977) 16 to 116X10+6 lb

(1981) 15X10+6 lb

For more U.S. Production (Complete) data for 1,4-Dichlorobenzene (9 total), please visit the HSDB record page.

35-40% for moth control; 35-40% as space deodorant; 25% or less for misc applications including use as a dye intermediate and in insecticide manufacture (1972)

Space deodorant, 55%; moth control, 35%; and other applications, 10% (1978)

CHEMICAL PROFILE: p-Dichlorobenzene. Demand: 1995: 70 million lb; 1996: 75 million lb; 2000 /projected/: 82 million lb.

Synthetic fabrics, which do not require proofing, as well as decline in consumption due to availability of less costly /equally efficient products will produce growth rate of 2 to 3%/year through 1983.

For more Consumption Patterns (Complete) data for 1,4-Dichlorobenzene (6 total), please visit the HSDB record page.

Chlorobenzenes are prepared industrially by reaction of liquid benzene with gaseous chlorine in the presence of a catalyst at moderate temperature and atmospheric pressure. ... Generally, mixtures of isomers and compounds with varying degrees of chlorination are obtained. ... Dichlorobenzenes are formed in this process as isomeric mixtures with a low content of the 1,3-isomer. A maximum dichlorobenzene yield of 98% is obtainable in a batch process in which 2 mol of chlorine per mol of benzene are reacted in the presence of ferric chloride and sulfur monochloride at mild temperatures. The remainder of the product consists of mono- and trichlorobenzene. About 75% para-dichlorobenzene, 25% ortho-dichlorobenzene and only 0.2% meta-dichlorobenzene are obtained.

Seven Star Moth Balls (American Eagle Home Products LLC): Active ingredient: paradichlorobenzene 99.9%.

Mothguard Old Fashioned Moth Balls (HBC Chemical LLC): Active ingredient: paradichlorobenzene 99.75%.

Paragon Moth Bars (HBC Chemical LLC): Active ingredient: paradichlorobenzene 99.75%.

Paragon Moth Flakes (HBC Chemical LLC): Active ingredient: paradichlorobenzene 99.9%.

For more Formulations/Preparations (Complete) data for 1,4-Dichlorobenzene (25 total), please visit the HSDB record page.

Cosmetics product ingredient: 1,4-Dichlorobenzene (p-Dichlorobenzene)

Information on 11 consumer products that contain p-Dichlorobenzene in the following categories is provided: