3,3'-dichlorobenzidine

H312: Harmful in contact with skin [Warning Acute toxicity, dermal]

H317: May cause an allergic skin reaction [Warning Sensitization, Skin]

H350: May cause cancer [Danger Carcinogenicity]

H400: Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H410: Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

P203, P261, P272, P273, P280, P302+P352, P317, P318, P321, P333+P317, P362+P364, P391, P405, and P501 (click each P-code to see the statement)

H312 (100%): Harmful in contact with skin [Warning Acute toxicity, dermal]

H317 (100%): May cause an allergic skin reaction [Warning Sensitization, Skin]

H350 (100%): May cause cancer [Danger Carcinogenicity]

H400 (100%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H410 (100%): Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

Aggregated GHS information provided per 56 reports by companies from 7 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website.

P273, P391, and P501 (click each P-code to see the statement)

H335: May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]

H341: Suspected of causing genetic defects [Warning Germ cell mutagenicity]

H351: Suspected of causing cancer [Warning Carcinogenicity]

P203, P261, P271, P280, P304+P340, P318, P319, P403+P233, P405, and P501 (click each P-code to see the statement)

P203, P273, P280, P318, P391, P405, and P501 (click each P-code to see the statement)

Fresh air, rest. Seek medical attention if you feel unwell.

Remove contaminated clothes. Rinse and then wash skin with water and soap. Seek medical attention if you feel unwell.

Rinse with plenty of water (remove contact lenses if easily possible).

Rinse mouth. 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.

SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. IMMEDIATELY call a hospital or poison control center even if no symptoms (such as redness or irritation) develop. IMMEDIATELY transport the victim to a hospital for treatment after washing the affected areas.

INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. IMMEDIATELY call a physician and be prepared to transport the victim to a hospital even if no symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing.

INGESTION: DO NOT INDUCE VOMITING. If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and IMMEDIATELY call a hospital or poison control center. Be prepared to transport the victim to a hospital if advised by a physician. If the victim is convulsing or unconscious, do not give anything by mouth, ensure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital.

OTHER: Since this chemical is a known or suspected carcinogen you should contact a physician for advice regarding the possible long term health effects and potential recommendation for medical monitoring. Recommendations from the physician will depend upon the specific compound, its chemical, physical and toxicity properties, the exposure level, length of exposure, and the route of exposure. (NTP, 1992)

(General first aid procedures)

Eye: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.

Skin: Soap wash immediately - If this chemical contacts the skin, immediately wash the contaminated skin with soap and water. If this chemical penetrates the clothing, immediately remove the clothing, wash the skin with soap and water, and get medical attention promptly.

Breathing: Respiratory support

Swallow: Medical attention immediately - If this chemical has been swallowed, get medical attention immediately.

This compound is not very flammable but any fire involving this compound may produce dangerous vapors. You should evacuate the area. All firefighters should wear full-body protective clothing and use self-contained breathing apparatuses. You should extinguish any fires involving this chemical with a dry chemical, carbon dioxide, foam, or halon extinguisher. (NTP, 1992)

Use fine water spray, dry powder, carbon dioxide.

Wear self contained breathing apparatus for fire fighting if necessary.

Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

SPILL: Increase the immediate precautionary measure distance, in the downwind direction, as necessary.

FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)

Personal protection: complete protective clothing including self-contained breathing apparatus. Do NOT let this chemical enter the environment. Sweep spilled substance into sealable containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations.

Use of sodium hypochlorite bleach solution to decontaminate 3,3'-dichlorobenzidine was partially effective. An aqueous solution of 5% tetrapotassium pyrophosphate and 10% sodium ethyl hexyl sulfate when blended in a jet sprayer effectively removed 3,3'-dichlorobenzidine from a worker area (90-99% reduction). Once removed from the work site and collected in a central location, it was then determined that the diazotization reaction (the addition of sulfate, ice and sodium nitrate occurred to eliminate any detectable dichlorobenzine from the washings.

PRECAUTIONS FOR "CARCINOGENS": A high-efficiency particulate arrestor (HEPA) or charcoal filters can be used to minimize amt of carcinogen in exhausted air ventilated safety cabinets, lab hoods, glove boxes or animal rooms ... Filter housing that is designed so that used filters can be transferred into plastic bag without contaminating maintenance staff is avail commercially. Filters should be placed in plastic bags immediately after removal ... The plastic bag should be sealed immediately ... The sealed bag should be labelled properly ... Waste liquids ... should be placed or collected in proper containers for disposal. The lid should be secured & the bottles properly labelled. Once filled, bottles should be placed in plastic bag, so that outer surface ... is not contaminated ... The plastic bag should also be sealed & labelled. ... Broken glassware ... should be decontaminated by solvent extraction, by chemical destruction, or in specially designed incinerators. /Chemical Carcinogens/

ACCIDENTAL RELEASE MEASURES /Personal precautions, protective equipment and emergency procedures/ Use personal protective equipment. Avoid dust formation. Avoid breathing vapours, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas. Avoid breathing dust.

Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoided.

Pick up and arrange disposal without creating dust. Sweep up and shovel. Keep in suitable, closed containers for disposal.

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number U073, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.

A potential candidate for rotary kiln incineration at a temperature range of 820 to 1,600 °C and residence times of seconds for liquids and gases, and hours for solids.

Incineration (820 °C, 0.5 sec for primary combustion; 1200 °C, 1.0 sec for secondary combustion). The formation of elemental chlorine can be prevented through injection of steam or methane into the combustion process. Nitrogen oxide may be abated through the use of thermal or catalytic devices. Recommendable method: Incineration. Not recommendable method: Discharge to sewer.

Incineration: (1500 °F, 0.5 sec for primary combustion; 2200 °F, 1.0 sec for secondary combustion). The formation of elemental chlorine can be prevented through injection of steam or methane into the combustion process. Nitrogen oxide may be abated through the use of thermal or catalytic devices.

For more Disposal Methods (Complete) data for 3,3'-DICHLOROBENZIDINE (11 total), please visit the HSDB record page.

Employees working with 3,3'-dichlorobenzidine (or its salts) within an isolated system, such as a "glove box" shall wash their hands and arms upon completion of the assigned task and before engaging in other activities not associated with the isolated system.

SRP: Contaminated protective clothing should be segregated in a manner such that there is no direct personal contact by personnel who handle, dispose, or clean the clothing. The completeness of the cleaning procedures should be considered before the decontaminated protective clothing is returned for reuse by the workers. Contaminated clothing should not be taken home at the end of shift, but should remain at employee's place of work for cleaning.

SRP: Local exhaust ventilation should be applied wherever there is an incidence of point source emissions or dispersion of regulated contaminants in the work area. Ventilation control of the contaminant as close to its point of generation is both the most economical and safest method to minimize personnel exposure to airborne contaminants. Ensure that the local ventilation moves the contaminant away from the worker.

Employees shall be required to shower after the last exit of the day.

For more Preventive Measures (Complete) data for 3,3'-DICHLOROBENZIDINE (23 total), please visit the HSDB record page.

SMALL SPILLS AND LEAKAGE: You should dampen the solid spill material with acetone, then transfer the dampened material to a suitable container. Use absorbent paper dampened with acetone to pick up any remaining material. Seal your contaminated clothing and the adsorbent paper in a vapor-tight plastic bag for eventual disposal. Solvent wash all contaminated surfaces with acetone followed by washing with a strong soap and water solution. Do not reenter the contaminate area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.

STORAGE PRECAUTIONS: You should protect this chemical from exposure to light. Keep the container tightly closed under an inert atmosphere, and store it in a freezer. (NTP, 1992)

Provision to contain effluent from fire extinguishing. Separated from food and feedstuffs. Well closed. Store only in original container. Store in an area without drain or sewer access.

Stable under recommended storage conditions.

PRECAUTIONS FOR "CARCINOGENS": Storage site should be as close as practical to lab in which carcinogens are to be used, so that only small quantities required for ... expt need to be carried. Carcinogens should be kept in only one section of cupboard, an explosion-proof refrigerator or freezer (depending on chemicophysical properties ...) that bears appropriate label. An inventory ... should be kept, showing quantity of carcinogen & date it was acquired ... Facilities for dispensing ... should be contiguous to storage area. /Chemical Carcinogens/

11 [mg/m3]

130 [mg/m3]

760 [mg/m3]

Ca See Appendix A

[1910.1007] See Appendix B

A potential occupational carcinogen. (NIOSH, 2024)

NIOSH considers 3,3'-dichlorobenzidine (and its salts) to be a potential occupational carcinogens.

Ca [N.D.]

See: IDLH INDEX

Exposure by all routes should be carefully controlled to levels as low as possible. Skin notation.

A3; Confirmed animal carcinogen with unknown relevance to humans.

(skin); A3 (confirmed animal carcinogen with unknown relevance to humans).

skin absorption (H); carcinogen category: 2

Evaporation at 20 °C is negligible; a harmful concentration of airborne particles can, however, be reached quickly when dispersed, especially if powdered.

The substance is irritating to the respiratory tract.

Repeated or prolonged contact with skin may cause dermatitis. The substance may have effects on the liver. This substance is probably carcinogenic to humans.

Excerpt from NIOSH Pocket Guide for 3,3'-Dichlorobenzidine (and its salts):

Skin: PREVENT SKIN CONTACT - Wear appropriate personal protective clothing to prevent skin contact.

Eyes: PREVENT EYE CONTACT - Wear appropriate eye protection to prevent eye contact.

Wash skin:

• WHEN CONTAMINATED - The worker should immediately wash the skin when it becomes contaminated.

• DAILY - The worker should wash daily at the end of each work shift, and prior to eating, drinking, smoking, etc.

Remove: WHEN WET OR CONTAMINATED - Work clothing that becomes wet or significantly contaminated should be removed and replaced.

Change: DAILY - Workers whose clothing may have become contaminated should change into uncontaminated clothing before leaving the work premises.

Provide:

• EYEWASH - Eyewash fountains should be provided in areas where there is any possibility that workers could be exposed to the substances; this is irrespective of the recommendation involving the wearing of eye protection.

• QUICK DRENCH - Facilities for quickly drenching the body should be provided within the immediate work area for emergency use where there is a possibility of exposure. [Note: It is intended that these facilities provide a sufficient quantity or flow of water to quickly remove the substance from any body areas likely to be exposed. The actual determination of what constitutes an adequate quick drench facility depends on the specific circumstances. In certain instances, a deluge shower should be readily available, whereas in others, the availability of water from a sink or hose could be considered adequate.] (NIOSH, 2024)

/Skin protection/ Handle with gloves.

/Eye/face protection/ Face shield and safety glasses Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).

PRECAUTIONS FOR "CARCINOGENS": ... Dispensers of liq detergent /should be available./ ... Safety pipettes should be used for all pipetting. ... In animal laboratory, personnel should ... wear protective suits (preferably disposable, one-piece & close-fitting at ankles & wrists), gloves, hair covering & overshoes. ... In chemical laboratory, gloves & gowns should always be worn ... however, gloves should not be assumed to provide full protection. Carefully fitted masks or respirators may be necessary when working with particulates or gases, & disposable plastic aprons might provide addnl protection. ... gowns ... /should be/ of distinctive color, this is a reminder that they are not to be worn outside the laboratory. /Chemical Carcinogens/

/Body Protection/ Complete suit protecting against chemicals, The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.

For more Personal Protective Equipment (PPE) (Complete) data for 3,3'-DICHLOROBENZIDINE (11 total), please visit the HSDB record page.

(See OSHA respirator requirements for selected chemicals)

At concentrations above the NIOSH REL, or where there is no REL, at any detectable concentration:

(APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode

(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus

(APF = 50) Any air-purifying, full-facepiece respirator with an N100, R100, or P100 filter.

Click here for information on selection of N, R, or P filters. 

Any appropriate escape-type, self-contained breathing apparatus

Important additional information about respirator selection

3,3'-dichlorobenzidine is a gray to purple crystalline powder. Insoluble in water. Very toxic. Used in the dye industry, curing agent for isocyanate terminated resins.

Gray to purple, crystalline solid; [NIOSH]

GREY-TO-PURPLE CRYSTALS.

Gray to purple, crystalline solid.

Needles from alcohol or benzene

White crystalline solid

Gray to purple, crystalline solid

788 °F at 760 mmHg (NIOSH, 2024)

402 °C @760 [mm Hg]

270 to 271 °F (NTP, 1992)

132.5 °C

132-133 °C

270-271 °F

0.07 % at 59 °F (NIOSH, 2024)

Solubility in water: 2-4% at 22 °C and pH 4.6 to pH 8.9 /Dihydrochloride salt/

In water, 3.1 mg/L at 25 °C

Moderately soluble in alcohol; readily soluble in ether

Soluble in acetic acid, benzene, and ethanol

Slightly soluble in dilute hydrochloric acid

Solubility in water: none

(59 °F): 0.07%

log Kow = 3.51

When heated to decomposition it emits very high toxic fumes of /hydrogen chloride and nitrogen oxides./

Weak base

pKa1 = 1.6; pKa2 = 3.2

153.3 Ų [M]+ [CCS Type: DT; Buffer gas: N2; Ionization: APCI+; Dataset: TOXCAST; Source Identifier: DTXSID1020433]

167.6 Ų [M+H]+ [CCS Type: DT; Buffer gas: N2; Ionization: ESI+; Dataset: TOXCAST; Source Identifier: DTXSID1020433]

Undergoes usual reactions of benzidine derivatives, e.g., formation of diazonium salts and alkyl derivatives

Conversion factor: ppm = 0.0966 times mg/cu m

When combined with ferric chloride or bleaching powder, a green color is produced.

Has general characteristics of primary aromatic amines

Crystal structure

Formula unit

Space group

Unit cell

Unit cell parameter

Hazardous Air Pollutants (HAPs)

Nitrogen Compounds -> Benzidine and Derivatives

Carcinogens

Mutagens

Insoluble in water.

Aryl Halides

Amines, Aromatic

A halide- and amine-substituted aromatic compound. Amines are chemical bases. They neutralize acids to form salts plus water. These acid-base reactions are exothermic. The amount of heat that is evolved per mole of amine in a neutralization is largely independent of the strength of the amine as a base. Amines may be incompatible with isocyanates, halogenated organics, peroxides, phenols (acidic), epoxides, anhydrides, and acid halides. Flammable gaseous hydrogen is generated by amines in combination with strong reducing agents, such as hydrides.

Strong oxidizing agents

None reported

CDC-ATSDR Toxicological Profile

IDENTIFICATION AND USE: 3,3'-Dichlorobenzidine (DCB) is gray to purple, crystalline solid. It is used in the United States primarily in the manufacture of pigments for printing ink, textiles, paper, paint, rubber, and plastics and as a curing agent for isocyanate-containing polymers and solid urethane plastics. HUMAN EXPOSURE AND TOXICITY: Dermal exposure to 3,3'-DCB base has caused dermatitis in dye workers. A significant increase in cancer of the blood cells (mostly leukemia) was found among dye-manufacturing workers exposed only to 3,3'-DCB. DCB is capable of inducing DNA damage and some cellular stress responses in HepG2 cells. It has caused unscheduled DNA synthesis in human fibroblasts. Effective biological monitoring was achieved by a combination of monitoring hemoglobin adducts with spot samplings of urinary DCB excretion. DCB is reasonably anticipated to be a human carcinogen. ANIMAL STUDIES: DCB or its dihydrochloride caused tumors in several species of experimental animals, at several different tissue sites, and by several different routes of exposure. Dietary administration of DCB caused mammary-gland cancer (adenocarcinoma) in rats of both sexes, granulocytic leukemia and Zymbal-gland cancer (carcinoma) in male rats, urinary-bladder cancer (transitional-cell or papillary transitional-cell carcinoma) in hamsters and in female dogs, and liver cancer (hepatocellular carcinoma) in female dogs. Subcutaneous injection of DCB caused skin and mammary-gland tumors in rats. Prenatal exposure to DCB in mice caused lymphoid leukemia, and dietary exposure caused liver cancer (hepatocellular carcinoma) in males. Purified and technical grade DCB had some direct mutagenic activity toward Salmonella typhimurium TA1538, but this was increased over 50-fold by activation. DCB injected ip into mice at low concentration increased, and at high concentration, decreased the sister chromatid exchange frequency in bone marrow cells.

3,3’-Dichlorobenzidine's mechanism of toxicity derives mainly from the adduction of DNA by its metabolites. The formation of nitroso derivatives during metabolism, yielding a sulfinic acid amide with hemoglobin in erythrocytes, is suggested to be a mechanism for this adduct formation. 3,3’-Dichlorobenzidine can act on the aryl hydrocarbon receptor to induce the activity of cytochrome p-450 enzymes, which metabolize 3,3’-dichlorobenzidine, along with other polyhalogenated aromatics, into their toxic intermediates. (L124, A89, A90)

3,3'-Dichlorobenzidine

Reproductive

Semi-Volatile Organic Compound (SVOC)

Smith, C.D. and Nowell, L.H., 2024. Health-Based Screening Levels for evaluating water-quality data (3rd ed.). DOI:10.5066/F71C1TWP

CLASSIFICATION: B2; probable human carcinogen. BASIS FOR CLASSIFICATION: Based on statistically significantly increased tumor incidence in rats, mice and dogs. Additional support is provided by positive evidence of genotoxicity and structural relationship to the known human bladder carcinogen benzidine. HUMAN CARCINOGENICITY DATA: Inadequate. ANIMAL CARCINOGENICITY DATA: Sufficient.

Inadequate evidence of carcinogenicity in humans. Sufficient evidence of carcinogenicity in animals. OVERALL EVALUATION: Group 2B: The agent is possibly carcinogenic to humans.

A3; Confirmed animal carcinogen with unknown relevance to humans.

3,3'-Dichlorobenzidine: reasonably anticipated to be a human carcinogen. /3,3'-Dichlorobenzidine and 3,3'-Dichlorobenzidine Dihydrochloride/

Group 2B: Possibly carcinogenic to humans

Volume 29: (1982) Some Industrial Chemicals and Dyestuffs

Volume Sup 7: Overall Evaluations of Carcinogenicity: An Updating of IARC Monographs Volumes 1 to 42, 1987; 440 pages; ISBN 92-832-1411-0 (out of print)

2B, possibly carcinogenic to humans. (L135)

The salt form of 3,3'-dichlorobenzidine may cause respiratory infections, stomach upset, and dermatitis. 3,3'-Dichlorobenzidine is also believed to be a possible carcinogen. (L124)

The substance can be absorbed into the body by inhalation of its aerosol, through the skin and by ingestion.

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

Oral (L124) ; inhalation (L124) ; dermal (L124)

Cough. Sore throat.

MAY BE ABSORBED!

Skin sensitization, dermatitis; headache, dizziness; caustic burns; frequent urination, dysuria; hematuria (blood in the urine); gastrointestinal upset; upper resp infection; [potential occupational carcinogen]

The salt form of 3,3'-dichlorobenzidine may cause sore throat, respiratory infections, stomach upset, headache, dizziness, caustic burns, and dermatitis. (L124)

Cancer, Dermal (Skin), Hepatic (Liver), Renal (Urinary System or Kidneys)

Bladder, liver, lung, skin, gastrointestinal tract

[in animals: liver & bladder cancer]

Occupational hepatotoxin - Secondary hepatotoxins: the potential for toxic effect in the occupational setting is based on cases of poisoning by human ingestion or animal experimentation.

IARC Carcinogen - Class 3: Chemicals are not classifiable by the International Agency for Research on Cancer.

NTP Carcinogen - Reasonably anticipated to be a human carcinogen.

ACGIH Carcinogen - Confirmed Animal.

IRIS Current

LD50: 8 g/kg (Dermal, Rat) (T24)

LD50: 3.82 g/kg (Oral, Rat) (T24)

LD50 Mouse (female) oral 352 mg/kg/day (7 consecutive days)

LD50 Mouse (male) oral 368 mg/kg/day (7 consecutive days)

LD50 Mouse (female) oral 488 mg/kg/day (7 consecutive days)

LD50 Rat oral 7,070 mg/kg /Admin in pure olive oil/

For more Non-Human Toxicity Values (Complete) data for 3,3'-DICHLOROBENZIDINE (7 total), please visit the HSDB record page.

Treatment for 3,3'-dichlorobenzidine poisoning is usually supportive. (L124)

Admin in conjunction with other chem: 9 groups of 22 (& 1 of 96) male Wistar rats were given the following cmpd alone or in sequence for a period of 4 wk per cmpd: Ortho-N-butyl-N-(4-hydroxybutyl)nitrosamine (0.01% in drinking-water), N-(4-(5-nitro-2-furyl)-2-thiazolyl)formamide (0.15% in diet), N-fluorenylacetamide (0.025% in diet), & 3,3'-dichlorobenzidine (0.3% in diet). An untreated control group consisted of 12 rats. The animals were killed when 40 wk old. 3,3'-Dichlorobenzidine when given in sequence with 1 or more of the other cmpd induced histological changes of liver (cystic change of bile ducts & oval cell proliferation) in 44-60% of animals (p< 0.05 when compared with ... /control group/). No change was seen in liver when 3'3-dichlorobenzidine was given alone. Incidence of urinary bladder tumors was not significantly incr when 3,3'-dichlorobenzidine was added to diet.

A synergistic role for 3,3'-dichlorobenzidine in the development of bladder cancer has been suggested. This was proposed in a study in which no carcinomas were found in any rats admin one of the following: 0.03% 3,3'-dichlorobenzidine in the diet, 0.001% BBN (N-butyl-N-(hydroxybutyl)nitrosamine) in drinking water, 0.0005% 2-acetylaminofluorene (2-AAF) in the diet, or 0.04% N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide (FANFT) in the diet for a period of 40 wk ... . However, when BBN plus 3,3'-dichlorobenzidine were fed together at the same dose levels as above, there was a marked incr in the presence of papillary or nodular hyperplasia in the rat bladder, and the appearance of one papilloma. Based on these findings, the authors suggested that 3,3'-dichlorobenzidine had a synergistic effect on the cacinogenicity of BBN. In rats sequentially admin BBN (0.01%), FANFT (0.15%), 2-AAF (0.025%), and 3,3'-dichlorobenzidine (0.03%) for 4 wk each, the incidence of bladder cancer after admin of the 4 chemicals was no different than after admin of the first 3, suggesting no interactive effect of any type for 3,3'-dichlorobenzidine ...

LC50; Species: Daphnia magna (Water Flea) age <24 hr neonate; Conditions: freshwater, renewal, 22.3. (22-22.6 °C), pH 8.43 (8.33-8.61), hardness 170 (163-183) mg/L CaCO3, alkalinity 108 (88-131) mg/L CaCO3, dissolved oxygen 98.4% (94.8-100.8%); Concentration: 1050 ug/L for 48 hr (95% confidence interval: 810-1360 ug/L) /98% purity/

LC50; Species: Pimephales promelas (Fathead Minnow) age 30 days, length 20 mm, weight 0.103 g; Conditions: freshwater, flow through, 22 (21.7-22.5) °C, pH 7.24 (6.76-7.54), hardness 51.6 (50.9-51.9) mg/L CaCO3, alkalinity 43 (36-46) mg/L CaCO3, dissolved oxygen 83.1% (73.7-88.5%); Concentration: 2080 ug/L for 96 hr /98% purity/

LC50; Species: Pimephales promelas (Fathead Minnow) age 30 days, length 20 mm, weight 0.103 g; Conditions: freshwater, flow through, 21.5 (20.7-22) °C, pH 6.83 (6.55-7.11), hardness 50.9 (50.1-52.7) mg/L CaCO3, alkalinity 49.6 (46.4-51.2) mg/L CaCO3, dissolved oxygen 81.2% (74.3-85.4%); Concentration: 1770 ug/L for 96 hr (95% confidence interval: 1640-1920 ug/L) /98% purity/

LC50; Species: Pimephales promelas (Fathead Minnow) age 30 days, length 15 mm, weight 0.053 g; Conditions: freshwater, static, 22.3 (21.8-22.7) °C, pH 6.67 (6.45-6.77), hardness 49 (47.9-49.9) mg/L CaCO3, alkalinity 49.7 (48.4-51.2) mg/L CaCO3, dissolved oxygen 76.7% (67.3-84%); Concentration: 1050 ug/L for 96 hr (95% confidence interval: 820-1340 ug/L) /98% purity/

For more Ecotoxicity Values (Complete) data for 3,3'-DICHLOROBENZIDINE (6 total), please visit the HSDB record page.

1.20e+00

5.10e+00

8.30e-03

3.60e-02

1.30e-01

7.50e+01

8.20e-04

4.50e-01

3.40e-04

Volatile

1.20e+02

5.10e+02

8.30e-01

3.60e+00

1.30e+01

The substance is toxic to aquatic organisms. The substance may cause long-term effects in the aquatic environment. It is strongly advised not to let the chemical enter into the environment.

3,3'-Dichlorobenzidine's production and use as an intermediate in the manufacture of dyes and pigments, as a compounding ingredient for rubbers and plastics, and as a curing agent for polyurethane elastomers may result in its release to the environment through various waste streams. However, strict regulations requiring its use in closed systems should limit its potential for release. If released to air, an estimated vapor pressure of 4.1X10-6 mm Hg at 25 °C indicates 3,3'-dichlorobenzidine will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase 3,3'-dichlorobenzidine will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 10 hours. Particulate-phase 3,3'-dichlorobenzidine will be removed from the atmosphere by wet and dry deposition. 3,3'-Dichlorobenzidine absorbs strongly at wavelengths >290 nm and has been shown to photolyze rapidly in aqueous solution; therefore, it is expected to be susceptible to direct photolysis by sunlight in all environmental media. If released to soil, 3,3'-dichlorobenzidine is expected to have low to no mobility based upon a Koc range in the range of 721-33,720 measured in a variety of soils and sediment samples. Aromatic amines like 3,3'-dichlorobenzidine are known to bind to soils containing a large organic carbon content due to the ability of the aromatic amino group to form covalent bonds with humic and fulvic material in soils; these complexes are often irreversibly bound and immobile. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 2.8X10-11 atm-cu m/mole. 3,3'-Dichlorobenzidine is not expected to volatilize from dry soil surfaces based upon its estimated vapor pressure. Biodegradation is expected to occur slowly in soils and it has been reported that 3,3'-dichlorobenzidine may last for months in soil. When incubated in soil under aerobic conditions, only 2% mineralization was observed in 32 weeks and no mineralization was observed under anaerobic conditions in 52 weeks. If released into water, 3,3'-dichlorobenzidine is expected to adsorb to suspended solids and sediment based upon the Koc data. Biodegradation is expected to occur slowly in water. A biodegradation half-life of about 150 days was observed in a lake sediment and water slurry. Half-lives of 4-26 weeks and 16-101 weeks have been estimated for the biodegradation of 3,3'-dichlorobenzidine in surface water and anaerobic groundwater, respectively. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's estimated Henry's Law constant. A BCF range of 43-856 in fish suggest that bioconcentration in aquatic organisms will be moderate to high. 3,3'-Dichlorobenzidine has been shown to undergo photolysis rapidly (half-life of approximately 1 minute) in aqueous solution which suggests that photolysis will be an important environmental fate process in surface waters exposed to sunlight. Hydrolysis is not an important environmental fate process. Occupational exposure to 3,3'-dichlorobenzidine may occur through inhalation and dermal contact with this compound at workplaces where 3,3'-dichlorobenzidine is produced or used. The general population may be exposed when living near factories or disposal sites, through plant effluents or groundwater contamination. An additional source of exposure is the use of consumer products containing benzidine congener-based dyes, which can be contaminated with the respective amine, and also via uptake of the dyes from those products and ensuing metabolization. (SRC)

3,3'-Dichlorobenzidine has not been reported to occur naturally(1).

3,3'-Dichlorobenzidine's production and use as an intermediate in the manufacture of dyes and pigments, as a compounding ingredient for rubbers and plastics, and as a curing agent for polyurethane elastomers(1) may result in its release to the environment through various waste streams(SRC). However strict regulations requiring its use in closed systems should limit its potential for release(2).

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values of 33,720 and 15,885 measured in two soils(2) and a Koc range of 721 to 3,965 measured in a variety of sediment soils(3) indicate that 3,3'-dichlorobenzidine is expected to have low to no mobility in soil(SRC). 3,3'-Dichlorobenzidine is a weak base with pKa values of 3.2 and 1.6(4), indicating that this compound will exist primarily in the neutral form. Aromatic amines like 3,3'-dichlorobenzidine and substituted anilines are known to bind to soils containing a large organic carbon content due to the ability of the aromatic amino group to form covalent bonds with humic and fulvic material in soils(5); these complexes are often irreversibly bound and immobile(5). Volatilization of 3,3'-dichlorobenzidine from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2.8X10-11 atm-cu m/mole(SRC), developed using a fragment constant estimation method(6). 3,3'-Dichlorobenzidine is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 4.1X10-6 mm Hg(SRC), determined from a fragment constant method(6). A 1% of theoretical BOD using activated sludge in the Japanese MITI test indicates that 3,3'-dichlorobenzidine is not readily biodegradable(7). Biodegradation is expected to occur slowly in soils(SRC) and it has been reported that 3,3'-dichlorobenzidine may last for months in soil(8). When incubated in soil under aerobic conditions, only 2% mineralization occurred in 32 weeks(2); under anaerobic conditions no mineralization occurred in a year(2). 3,3'-Dichlorobenzidine absorbs strongly at wavelengths >290 nm(9) and has been shown to photolyze rapidly in aqueous solution(10); therefore, it may be susceptible to direct photolysis on soil surfaces exposed to sunlight(SRC).[(1) Swann RL et al; Res Rev 85: 17-28 (1983) (2) Boyd SA et al; Environ Toxicol Chem 3: 201-8 (1984) (3) Donaldson FP, Nyman MC; Environ Toxicol Chem 24: 1022-28 (2005) (4) Nyman MC et al; Environ Sci Technol 31: 1068-73 (1997) (5) Adrian P et al; Chemosphere 18: 1599-609 (1989) (6) US EPA; Estimation Program Interface (EPI) Suite. Ver. 4.11. Nov, 2012. Available from, as of Mar 21, 2015: http://www.epa.gov/oppt/exposure/pubs/episuitedl.htm (7) NITE; Chemical Risk Information Platform (CHRIP). Biodegradation and Bioconcentration. Tokyo, Japan: Natl Inst Tech Eval. Available from, as of Mar 22, 2015: http://www.safe.nite.go.jp/english/db.html (8) USEPA; High Production Volume (HPV) Challenge Program. Test Plan for 3,3-Dichlorobenzidine Dihydrochloride (CAS No. 612-83-9), June 2006. Available from, as of Mar 21, 2015: http://www.epa.gov/chemrtk/pubs/summaries/viewsrch.htm (9) NIST; NIST Chemistry WebBook.

AQUATIC FATE: Based on a classification scheme(1), Koc values of 33,720 and 15,885 measured in two soils(2) and a Koc range of 721 to 3,965 measured in a variety of sediments(3) indicate that 3,3'-dichlorobenzidine is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(4) based upon an estimated Henry's Law constant of 2.8X10-11 atm-cu m/mole(SRC), developed using a fragment constant estimation method(5). According to a classification scheme(6), a BCF range of 43-856 measured in fish(7-9), suggest bioconcentration in aquatic organisms is moderate to high. A 1% of theoretical BOD using activated sludge in the Japanese MITI test indicates that 3,3'-dichlorobenzidine is not readily biodegradable(9). 3,3'-Dichlorobenzidine is expected to biodegrade slowly in water. The half-life of 3,3'-dichlorobenzidine in a lake water and sediment slurry was approximately 150 days(2). Half-lives of 4-26 weeks and 16-101 weeks have been estimated for the biodegradation of 3,3'-dichlorobenzidine in surface water and anaerobic groundwater, respectively(11). 3,3'-Dichlorobenzidine has been shown to undergo rapid photolysis in aqueous solution yielding monochlorobenzidine, benzidine and other water insoluble products(12,13). The short half-life of this reaction (approximately 1 minute)(13) suggests that photolysis in sunlit surface waters will be an important environmental fate process(SRC). Hydrolysis is not an important environmental fate process for 3,3'-dichlorobenzidine(14).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 3,3'-dichlorobenzidine, which has an estimated vapor pressure of 4.1X10-6 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase 3,3'-dichlorobenzidine 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 10 hours(SRC), calculated from its rate constant of 4.0X10-11 cu cm/molecule-sec at 25 °C(SRC) determined using a structure estimation method(2). 3,3'-Dichlorobenzidine absorbs strongly at wavelengths >290 nm(3) and has been shown to photolyze rapidly in aqueous solution(4); therefore, it is expected to be susceptible to direct photolysis by sunlight(SRC). Particulate-phase 3,3'-dichlorobenzidine may be removed from the air by wet and dry deposition(SRC).[(1) Bidleman TF; Environ Sci Technol 22: 361-367 (1988) (2) US EPA; Estimation Program Interface (EPI) Suite. Ver. 4.11. Nov, 2012. Available from, as of Mar 21, 2015: http://www.epa.gov/oppt/exposure/pubs/episuitedl.htm (3) NIST; NIST Chemistry WebBook.

3,3-Dichlorobenzidine, present at 3 mg/L dissolved organic carbon, was 9-43% 0-91%, 34-93% and 18-99% biodegraded in 4 weeks using an activated sludge inoculum, amended with a yeast extract nutrient broth of 50, 100, 200 and 400 mg/L, respectively, in the Modified AFNOR test. No biodegradation was observed in tests not amended with the yeast extract(1). When incubated with natural aquatic communities from eutrophic and mesotrophic lakes, 25% of the 3,3'-dichlorobenzidine degraded in a month(2). When incubated in soil under aerobic conditions, only 2% mineralization occurred in 32 weeks and no degradation intermediates were detected(3). Under anaerobic conditions no mineralization occurred in a year(3). 3,3'-Dichlorobenzidine, present at 100 mg/L, achieved 1% of its theoretical BOD in 4 weeks using an activated sludge inoculum at 30 mg/L and the Japanese MITI test which classified the compound as not readily biodegradable(4). The half-life of 3,3'-dichlorobenzidine in a lake water and sediment slurry obtained from Lake Macatawa, MI was approximately 150 days(5). 3,3'-Dichlorobenzidine dihydrochloride was not readily biodegradable by microorganisms obtained from freshwater lakes and incubated for 28 and 30 days or in an activated sludge study(6,7). These data suggest that biodegradation of 3,3'-dichlorobenzidine will occur slowly in the environment(SRC). Half-lives of 4-26 weeks and 16-101 weeks have been estimated for the biodegradation of 3,3'-dichlorobenzidine in surface water and anaerobic groundwater, respectively(8).

The rate constant for the vapor-phase reaction of 3,3'-dichlorobenzidine with photochemically-produced hydroxyl radicals has been estimated as 4.0X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 10 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). 3,3'-Dichlorobenzidine absorbs strongly at wavelengths >290 nm(2) and, therefore, is expected to be susceptible to direct photolysis by sunlight(SRC). 3,3'-Dichlorobenzidine dihydrochloride was shown to undergo rapid photolysis in aqueous solution yielding monochlorobenzidine, benzidine and other water insoluble products(3). The half-life of 3,3'-dichlorobenzidine in aqueous solution irradiated at 310 nm was approximately 1 minute(4). The photolysis half-life of 3,3'-dichlorobenzidine dihydrochloride in water is reported to be 5-30 minutes under artificial laboratory light and 90 seconds in direct natural sunlight(5). The hydrolysis half-life of 3,3'-dichlorobenzidine has been estimated as 100 days based on surrogate substances(5). Zero hydrolysis was observed after 5 days at 50 °C(5). 3,3'-Dichlorobenzidine is an aromatic amine and aromatic amines in surface waters exposed to sunlight react with photo-oxidants (such as hydroxyl radicals, peroxy radicals and singlet oxygen) with a half-life on the order of 30 days(6).[(1) US EPA; Estimation Program Interface (EPI) Suite. Ver. 4.11. Nov, 2012. Available from, as of Mar 21, 2015: http://www.epa.gov/oppt/exposure/pubs/episuitedl.htm (2) NIST; NIST Chemistry WebBook.

The equilibrium bioconcentration factors using (14)-C-3,3'-dichlorobenzidine in whole bluegill sunfish (Lepomis macrochirus) was reported as 495-507, the BCF was 114-175 in the edible portion and 814-856 in non-edible parts(1). The BCF values measured in Golden ide fish (Leuciscus idus) and in algae were 610 and 940, respectively(2). A BCF range of 43-213 was measured in fish for 3,3'-dichlorobenzidine(SRC), using carp (Cyprinus carpio) which were exposed over an 8-week period(3). According to a classification scheme(4), these BCF data suggest the potential for bioconcentration in aquatic organisms is moderate to high(SRC).

Based upon measured Freundlich adsorption coefficients in a Brookston clay loam soil and a Rubicon sandy soil(1), the Koc of 3,3'-dichlorobenzidine can be determined to be 33,720 and 15,885 in the respective soils(SRC). Batch isotherm studies using five sandy to silty-clay sediment samples collected from Lake Macatawa (Holland, MI), measured Koc values ranging from 721 to 3,965(2); the majority of adsorption was determined to occur through covalent bonding(2). According to a classification scheme(3), these Koc values suggest that 3,3'-dichlorobenzidine is expected to have low to no mobility in soil. 3,3'-Dichlorobenzidine is a weak base with pKa values of 3.2 and 1.6(4), indicating that this compound will exist primarily in the neutral form. Aromatic amines like benzidine, 3,3'-dichlorobenzidine and substituted anilines are known to bind to soils containing a large organic carbon content due to the ability of the aromatic amino group to form covalent bonds with humic and fulvic material in soils(5). These complexes are often irreversibly bound and immobile(5).

The Henry's Law constant for 3,3'-dichlorobenzidine is estimated as 2.8X10-11 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that 3,3'-dichlorobenzidine is expected to be essentially nonvolatile from water surfaces(2). 3,3'-Dichlorobenzidine's Henry's Law constant(1) indicates that volatilization from moist soil surfaces is not expected to occur(SRC). 3,3'-Dichlorobenzidine is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 4.1X10-6 mm Hg(SRC), determined from a fragment constant method(1). No 3,3'-dichlorobenzidine was lost from soil due to volatilization during persistance studies over 32 and 52 weeks under aerobic and anaerobic conditions, respectively(3).

DRINKING WATER: The concentration of 3,3'-dichlorobenzidine in drinking water wells near a waste disposal lagoon ranged from 0.13-0.27 ppm(1).

SURFACE WATER: 3,3'-Dichlorobenzidine was identified, not quantified, in the Besos River, Spain(1). 3,3-Dichlorobenzidine was identified, but not quantified, in the Potomac River, MD(2).

Analysis of purge wells and seepage water near a waste disposal lagoon receiving DCB-manufacture wastes showed levels of dichlorobenzidine ranging from 0.13 to 0.27 mg/L(1).

... Analysis of water of the Sumida River in Tokyo during 1964. ... Calorimetric analysis revealed that total aromatic amine content of the water (including 3,3'-dichlorobenzidine) reached levels up to 0.562 mg/L, although levels of DCB itself were not quantified(1).

3,3'-Dichlorobenzidine was identified in the following effluents: wastewater from metal finishing, max concentration of 10 ppb; nonferrous metals manufacture, 2.0 ppb maximum, 0.3 ppb average; paint and ink formulation, 10 ppb maximum; coal mining, 3 ppb maximum(1). 3,3'-Dichlorobenzidine was not detected in a nationwide urban runoff program (51 catchments in 19 cities-86 total samples)(2). 3,3'-Dichlorobenzidine levels in the wasterwater effluent from a Toronto Canada company reportedly decreased from over 600 ug/L in 1996 to 1.6 ug/L in 2001(3). Trace levels of 3,3'-dichlorobenzidine, 0.013 and 0.032 ug/L, were detected in wastewater samples from two metal plating companies(3). 3,3'-Dichlorobenzidine concentrations of 2.60 to 654.0 ppb were detected in various industrial wastewater composites between 1996 and 1998 in Canada(4).

The USEPA STORET database showed that no 3,3'-dichlorobenzidine was detected in 347 sediment samples at a detection limit of 1 mg/kg (dry weight)(1). 3,3'-Dichlorobenzidine was identified, not quantified, in sediment/soil/water mixture obtained from contaminated areas of Love Canal, NY(2). Sediment samples collected from Lake Macatawa (Holland, MI) between 1993 and 2003 contained 3,3'-dichlorobenzidine concentrations ranging from 0.008 to 69.663 mg/kg (most were less than 0.07 mg/kg)(3); 11 of 37 samples collected were below detection limits and reported as not detectable(3). 3,3'-Dichlorobenzidine levels of 0.01-0.04 were detected in Canadian agricultural soils(4).

The USEPA STORET database indicated that no 3,3'-dichlorobenzidine was detected in 83 biota samples at detection limit of 2.5 mg/kg (wet weight)(1).

According to the 2012 TSCA Inventory Update Reporting data, 3 reporting facilities estimate the number of persons reasonably likely to be exposed during the manufacturing, processing, or use of 3,3'-dichlorobenzidine dihydrochloride (CAS 612-83-9) in the United States may be as low as <10 workers and as high as 25-49 workers per plant; the data may be greatly underestimated due to confidential business information (CBI) or unknown values(1).

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number U073, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.

A potential candidate for rotary kiln incineration at a temperature range of 820 to 1,600 °C and residence times of seconds for liquids and gases, and hours for solids.

Incineration (820 °C, 0.5 sec for primary combustion; 1200 °C, 1.0 sec for secondary combustion). The formation of elemental chlorine can be prevented through injection of steam or methane into the combustion process. Nitrogen oxide may be abated through the use of thermal or catalytic devices. Recommendable method: Incineration. Not recommendable method: Discharge to sewer.

Incineration: (1500 °F, 0.5 sec for primary combustion; 2200 °F, 1.0 sec for secondary combustion). The formation of elemental chlorine can be prevented through injection of steam or methane into the combustion process. Nitrogen oxide may be abated through the use of thermal or catalytic devices.

For more Disposal Methods (Complete) data for 3,3'-DICHLOROBENZIDINE (11 total), please visit the HSDB record page.

PRECAUTIONS FOR "CARCINOGENS": Procurement ... of unduly large amt ... should be avoided. To avoid spilling, carcinogens should be transported in securely sealed glass bottles or ampoules, which should themselves be placed inside strong screw-cap or snap-top container that will not open when dropped & will resist attack from the carcinogen. Both bottle & the outside container should be appropriately labelled. ... National post offices, railway companies, road haulage companies & airlines have regulations governing transport of hazardous materials. These authorities should be consulted before ... material is shipped. /Chemical Carcinogens/

PRECAUTIONS FOR "CARCINOGENS": When no regulations exist, the following procedure must be adopted. The carcinogen should be enclosed in a securely sealed, watertight container (primary container), which should be enclosed in a second, unbreakable, leakproof container that will withstand chem attack from the carcinogen (secondary container). The space between primary & secondary container should be filled with absorbent material, which would withstand chem attack from the carcinogen & is sufficient to absorb the entire contents of the primary container in the event of breakage or leakage. Each secondary container should then be enclosed in a strong outer box. The space between the secondary container & the outer box should be filled with an appropriate quantity of shock-absorbent material. Sender should use fastest & most secure form of transport & notify recipient of its departure. If parcel is not received when expected, carrier should be informed so that immediate effort can be made to find it. Traffic schedules should be consulted to avoid ... arrival on weekend or holiday ... /Chemical Carcinogens/

Do not transport with food and feedstuffs.

Symbol: T, N; R: 45-21-43-50/53; S: 53-45-60-61; Note: E