Benzidine

H302: Harmful if swallowed [Warning Acute toxicity, oral]

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, P264, P270, P273, P280, P301+P317, P318, P330, P391, P405, and P501 (click each P-code to see the statement)

H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]

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

H400 (98.8%): 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 80 reports by companies from 4 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.

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

H372: Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure]

H373: May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure]

H401: Toxic to aquatic life [Hazardous to the aquatic environment, acute hazard]

H411: Toxic to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

P203, P260, P264, P270, P273, P280, P301+P317, P318, P319, P330, P391, P405, and P501 (click each P-code to see the statement)

Fresh air, rest.

Remove contaminated clothes. Rinse and then wash skin with water and soap. Wear protective gloves when administering first aid.

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

Rinse mouth.

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:

· Call 911 or emergency medical service.

· Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination.

· Move victim to fresh air if it can be done safely.

· Administer oxygen if breathing is difficult.

· If victim is not breathing:

-- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance.

-- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped with a one-way valve or other device).

-- If no pulse detected or no respiratory medical device available, provide continuous compressions. Conduct a pulse check every two minutes or monitor for any signs of spontaneous respirations.

· Remove and isolate contaminated clothing and shoes.

· For minor skin contact, avoid spreading material on unaffected skin.

· In case of contact with substance, remove immediately by flushing skin or eyes with running water for at least 20 minutes.

· For severe burns, immediate medical attention is required.

· Effects of exposure (inhalation, ingestion, or skin contact) to substance may be delayed.

· Keep victim calm and warm.

· Keep victim under observation.

· For further assistance, contact your local Poison Control Center.

· Note: Basic Life Support (BLS) and Advanced Life Support (ALS) should be done by trained professionals.

Specific First Aid:

· For corrosives, in case of contact, immediately flush skin or eyes with running water for at least 30 minutes. Additional flushing may be required.

· Removal of solidified molten material from skin requires medical assistance.

In Canada, an Emergency Response Assistance Plan (ERAP) may be required for this product. Please consult the shipping paper and/or the "ERAP" section.

(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.

Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]:

SMALL FIRE: Dry chemical, CO2 or water spray.

LARGE FIRE: Dry chemical, CO2, alcohol-resistant foam or water spray. If it can be done safely, move undamaged containers away from the area around the fire. Dike runoff from fire control for later disposal.

FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Do not get water inside containers. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames. (ERG, 2024)

Use water spray, foam, powder, carbon dioxide.

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.) Use water in flooding quantities as fog. Use foam, dry chemical, or carbon dioxide.

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.

· Keep unauthorized personnel away.

· Stay upwind, uphill and/or upstream.

· Ventilate closed spaces before entering, but only if properly trained and equipped.

· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.

· Do not touch damaged containers or spilled material unless wearing appropriate protective clothing.

· Stop leak if you can do it without risk.

· Prevent entry into waterways, sewers, basements or confined areas.

· Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers.

· DO NOT GET WATER INSIDE CONTAINERS.

Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (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)

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.

· For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances.

· For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind direction, as necessary.

· 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.

Personal protection: chemical protection suit 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.

Cover the spill with a 9:1 mixture of sand and soda ash.

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/

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number U021, 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. A potential candidate for fluidized bed incineration at a temperature range of 450 to 980 °C and residence times of seconds for liquids and gases, and longer for solids.

The following wastewater treatment technologies have been investigated for benzidine: Concentration process: Biological treatment.

This compound should be susceptible to removal from waste water by air stripping.

For more Disposal Methods (Complete) data for BENZIDINE (12 total), please visit the HSDB record page.

REGULATIONS IN USA CONCERNING BENZIDINE DESIGNATE STRICT PROCEDURES TO AVOID WORKER CONTACT: MIXT CONTAINING 0.1% OR MORE ... MUST BE MAINTAINED IN ISOLATED OR CLOSED SYSTEMS, EMPLOYEES MUST OBSERVE SPECIAL PERSONAL HYGIENE RULES, & CERTAIN PROCEDURES MUST BE FOLLOWED ... IN CASE OF ... EMERGENCIES ... .

RECOMMENDATIONS REGARDING THE HANDLING AND USE OF BENZIDINE IN CRIME RESEARCH LABS ALONG WITH WARNING NOTICES WHICH SHOULD BE USED ON BENZIDINE CONTAINERS ARE SUGGESTED.

If material not on fire and not involved in fire: Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers.

On exit from a regulated area employees should shower and change into street clothes, leaving their protective clothing and equipment at the point of exit to be placed in impervious containers at the end of the work shift for decontamination or disposal. Effective methods should be used to clean and decontaminate gloves and clothing.

For more Preventive Measures (Complete) data for BENZIDINE (20 total), please visit the HSDB record page.

Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS. (ERG, 2024)

Provision to contain effluent from fire extinguishing. Separated from strong oxidants and food and feedstuffs. Keep in the dark. Well closed. Store in an area without drain or sewer access.

KEEP WELL CLOSED & PROTECTED FROM LIGHT.

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/

· Wear positive pressure self-contained breathing apparatus (SCBA).

· Wear chemical protective clothing that is specifically recommended by the manufacturer when there is NO RISK OF FIRE.

· Structural firefighters' protective clothing provides thermal protection but only limited chemical protection.

0.024 [mg/m3]

10 [mg/m3]

61 [mg/m3]

Ca See Appendix ASee Appendix C

[1910.1010] See Appendix BSee Appendix C

A potential occupational carcinogen. (NIOSH, 2024)

NIOSH considers benzidine to be a potential occupational carcinogen.

Ca [N.D.]

See: IDLH INDEX

Exposure by all routes should be carefully controlled to levels as low as possible; skin

A1; Confirmed human carcinogen. skin notation.

A1 (confirmed human carcinogen); (skin).

carcinogen category: 1.

Small Fire

· Dry chemical, CO2 or water spray.

Large Fire

· Dry chemical, CO2, alcohol-resistant foam or water spray.

· If it can be done safely, move undamaged containers away from the area around the fire.

· Dike runoff from fire control for later disposal.

Fire Involving Tanks, Rail Tank Cars or Highway Tanks

· Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles.

· Do not get water inside containers.

· Cool containers with flooding quantities of water until well after fire is out.

· Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank.

· ALWAYS stay away from tanks in direct contact with flames.

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

This substance is carcinogenic to humans.

Excerpt from NIOSH Pocket Guide for Benzidine:

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.

Benzidine appears as a grayish-yellow to grayish-red, crystalline solid. Toxic by ingestion, inhalation, and skin absorption. Combustion produces toxic oxides of nitrogen. Used to make other chemicals and in chemical and biological analysis.

Grayish-yellow, reddish-gray, or white crystalline powder. Note: Darkens on exposure to air and light; [NIOSH]

COLOURLESS OR REDDISH CRYSTALLINE POWDER. TURNS DARK ON EXPOSURE TO AIR AND LIGHT.

Grayish-yellow, reddish-gray, or white crystalline powder. [Note: Darkens on exposure to air and light.]

White or slightly-reddish, crystalline powder

Grayish-yellow, reddish-gray, or white crystalline powder [Note: Darkens on exposure to air and light].

752 °F at 740 mmHg (NTP, 1992)

401 °C @760 [mm Hg]

262 °F (NTP, 1992)

less than 1 mg/mL at 72 °F (NTP, 1992)

1 g dissolves in 2500 ml cold water; 1 g dissolves in 107 ml boiling water; 1 g dissolves in 5 ml boiling alcohol; 1 g dissolves in 50 ml ether

In water, 322 mg/l @ 25 °C

0.322 mg/mL at 25 °C

Solubility in water, g/100ml at 25 °C:

(54 °F): 0.04%

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

1.250 @ 20 °C/4 °C

1.3 g/cm³

1.25 @ 20°C

6.36 (NTP, 1992) - Heavier than air; will sink (Relative to Air)

6.36 (Air = 1)

Relative vapor density (air = 1): 6.4

Low (NIOSH, 2024)

0.0000009 [mmHg]

log Kow= 1.34

DARKENS ON EXPOSURE TO AIR & LIGHT

... The influence of glucuronidation in the metabolism and carcinogenicity of benzidine was determined using dog liver slices and microsomes. This study demonstrated that the half lives of purified N-benzidine glucuronide in dog urine at 37 °C were 99, 25, and 3 min at pH 7.3, 6.3, and 5.3, respectively. It was also shown ... that the N-glucuronide of benzidine was stable in dog plasma at pH 9.3.

When heated to decomp it emits highly toxic fumes of /nitrogen oxides/.

pKa1= 4.3 pKa2= 3.3

Although benzidine can be protonated to form a cation which cannot volatilize from water, the pKa values of the diprotonated and monoprotonated conjugate acids of benzidine have been reported as 3.3 and 4.5, respectively. Therefore, dissolved benzidine will be present almost entirely in the form of a free base in naturally occurring waters.

156.9 Ų [M+H]+ [CCS Type: DT; Buffer gas: N2; Ionization: APCI+; Dataset: TOXCAST; Source Identifier: DTXSID2020137]

157.0 Ų [M+H]+ [CCS Type: DT; Buffer gas: N2; Ionization: ESI+; Dataset: TOXCAST; Source Identifier: DTXSID2020137]

139.4 Ų [M]+ [CCS Type: DT; Buffer gas: N2; Ionization: APCI+; Dataset: TOXCAST; Source Identifier: DTXSID2020137]

CAN BE MADE TO SUBLIME

WEAK BASE THAT FORMS INSOL SALTS WITH SULFURIC ACID: CAN BE DIAZOTIZED & OXIDIZED, & AMINO GROUPS CAN BE ACETYLATED & ALKYLATED

CONVERSION FACTOR: 1 PPM= 0.133 MG/CU M

Chemical structure

Clearing parameter

Crystal structure

Crystal-to-crystal transition

Darkens on exposure to air and light. Soluble in hot water.

Amines, Aromatic

BENZIDINE forms insoluble salts with sulfuric acid. Can be diazotized, acetylated and alkylated. Is hypergolic with red fuming nitric acid (NTP, 1992). Neutralizes acids in exothermic reactions to form salts plus water. May be incompatible with isocyanates, halogenated organics, peroxides, phenols (acidic), epoxides, anhydrides, and acid halides. Flammable gaseous hydrogen may be generated in combination with strong reducing agents, such as hydrides.

Benzidine is hypergolic (will ignite spontaneously) with red fuming nitric acid.

Red fuming nitric acid.

Red fuming nitric acid

CDC-ATSDR Toxicological Profile

N-acetylated benzidine metabolites are believed to form adducts with nucleic acids. Carcinogenesis is initiated when they are activated by peroxidation by prostaglandin H synthetase, oxidation by cytochrome P-450, or O-esterification by O-acetyltransferase or N,O-acetyltransferase. Benzidine has also been shown to bind to RNA and hemoglobin. (L95, A55)

Benzidine

3 x 10 ^-3 mg/kg-day

Semi-Volatile Organic Compound (SVOC)

0.0001−0.01

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

CLASSIFICATION: A; human carcinogen. BASIS FOR CLASSIFICATION: Observation of increased incidence of bladder cancer and bladder cancer-related deaths in exposed workers. HUMAN CARCINOGENICITY DATA: Sufficient.

Sufficient evidence of carcinogenicity in humans. Sufficient evidence of carcinogenicity in animals. OVERALL EVALUATION: Group 1: The agent is carcinogenic to humans.

A1; Confirmed human carcinogen.

Benzidine: known to be a human carcinogen.

Group 1: 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)

Volume 99: (2010) Some Aromatic Amines, Organic Dyes, and Related Exposures

Volume 100F: (2012) Chemical Agents and Related Occupations

1, carcinogenic to humans. (L135)

Benzidine is a known human carcinogen, most often associated with cancer of the urinary bladder. If benzidine comes in contact with skin it may cause a skin allergy. Liver, kidney, immune, and neurological effects have also been observed in animals exposed to benzidine. (L95)

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 (L95) ; inhalation (L95) ; dermal (L95)

MAY BE ABSORBED!

hematuria (blood in the urine); secondary anemia from hemolysis; acute cystitis; acute liver disorders; dermatitis; painful, irreg urination; [potential occupational carcinogen]

Cancer, Gastrointestinal (Stomach and Intestines, part of the digestive system), Hepatic (Liver), Renal (Urinary System or Kidneys)

Bladder, skin, kidneys, liver, blood

[liver, kidney & 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.

Methemoglobinemia - The presence of increased methemoglobin in the blood; the compound is classified as secondary toxic effect

IARC Carcinogen - Class 1: International Agency for Research on Cancer classifies chemicals as established human carcinogens.

NTP Carcinogen - Known to be a human carcinogen.

ACGIH Carcinogen - Confirmed Human.

IRIS Current

HEAST Current

LD50: 309 mg/kg (Oral, Rat) (T14)

LD50: 110 mg/kg (Intraperitoneal, Mouse) (T14)

Inhalation cancer potency factor: 2.3X10+2 (mg/kg/day)-1

Oral cancer potency factor: 2.3X10+2 (mg/kg/day)-1

LD50 Rat oral 309 mg/kg

LD50 Mouse oral 214 mg/kg

LD50 Mouse ip 110 mg/kg

Continuous administration of neozone D to dogs and rats failed to reveal its carcinogenicity. Nor did the agent potentiate the carcinogenic effect of benzidine in rats. Conversely, neozone D was found to inhibit benzidine induced carcinogenesis in female rats.

LC50 Gammarus pseudolimnaeus (scud) > 20,000 ug/l/96 hr /Conditions of bioassay not specified/

Pimephales promelas (fathead minnow) > 20,000 ug/l/96 hr /Conditions of bioassay not specified/

LC50 Salmo gairdneri (rainbow trout) 7400 ug/l/96 hr in a static unmeasured bioassay

LC50 Salvelinus namaycush 4350 ug/l/96 hr in a static unmeasured bioassay

For more Ecotoxicity Values (Complete) data for BENZIDINE (6 total), please visit the HSDB record page.

5.30e-04

1.00e-02

1.80e-04

1.10e-04

5.00e+00

2.30e+02

6.70e-02

3.00e-03

Volatile

5.30e-02

1.00e+00

1.50e-03

1.80e-02

1.10e-02

The substance is very toxic to aquatic organisms. It is strongly advised not to let the chemical enter into the environment.

Benzidine's former production and use in the manufacture of azo dyes, a reagent for the detection of blood, and rubber compounding agent may have resulted in its release to the environment through various waste streams. Today, benzidine may only be produced for captive use in the United States and its direct release to the environment is unlikely. When released to air, an estimated vapor pressure of 7X10-7 mm Hg at 25 °C indicates benzidine will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase benzidine 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 2 hours. Benzidine absorbs light in the environmental UV spectrum and may also undergo direct photolysis in the atmosphere. Particulate-phase benzidine will be removed from the atmosphere by wet and dry deposition. If released to soil, benzidine is expected to be essentially immobile based upon Koc values in the range of 227,000 to 882,000, measured in 4 soils. Benzidine is a weak base with 2 amine functional groups having pKa values of 4.3 and 3.3. These values indicate that benzidine can partially exist in the protonated form under acidic conditions. Volatilization from moist soil surfaces is not expected to be an important fate process because cations do not volatilize, and the estimated Henry's Law constant of the neutral species (free base) is 5.2X10-11 atm-cu m/mole. Benzidine is not expected to volatilize from dry soil surfaces based on its estimated vapor pressure. Benzidine is resistant to biodegradation at high concentrations due to its microbial toxicity, however it has been shown to undergo biodegradation at concentrations in the ppb range. Benzidine is oxidized rapidly by Fe(III) and other cations which are frequently found in soil and water. If released into water, benzidine is expected to adsorb to suspended solids and sediment based upon the Koc values. Volatilization from water surfaces is not expected to be an important fate process for either the free base or its conjugate acid based upon this compound's estimated Henry's Law constant and the fact that cations are non-volatile. Benzidine has been shown to undergo degradation in aerated water samples upon illumination with UV light, suggesting that photolysis in sunlit surface waters may occur. Benzidine is not expected to undergo hydrolysis due to a lack of hydrolyzable functional groups. BCF values of 40 and 55, measured in fish, suggest bioconcentration in aquatic organisms is moderate. Since benzidine may only be produced for captive use in the United States, the general population will not be exposed to this compound. Workers employed at laboratories where benzidine is made for research purposes, may be exposed to small quantities of benzidine via inhalation or dermal contact during its production or use. (SRC)

Benzidine's former production and use in the manufacture of azo dyes, a reagent for the detection of blood, and rubber compounding agent(1), may have resulted in its release to the environment through various waste streams. In 1973, OSHA regulations effectively banned the US production of benzidine, and today, benzidine may only be produced for captive use and maintained under closed systems with stringent workplace controls(1).

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values in the range of 227,000 to 882,000, measured in 4 soils(2), indicate that benzidine is expected to be essentiallyo immobile in soil(SRC). Benzidine is a weak base with 2 amine functional groups having pKa values of 4.3 and 3.3(3). These values indicate that benzidine can partially exist in the protonated form under acidic conditions(SRC). Volatilization of the neutral species of benzidine from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 5.2X10-11 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). The conjugate acid will not volatilize since cations are non-volatile(SRC). Benzidine is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 7X10-7 mm Hg(SRC), determined from a fragment constant method(5). Benzidine is generally resistant to biodegradation in soil at high concentrations, but may biodegrade at lower concentrations(SRC). Aqueous solutions of benzidine (0.01%) were reported to be stable for 9 weeks to degradation by soil/river water inoculum(6). In Drummer silty clay loam, benzidine applied at a concn of 10 ppb was degraded 79% after 4 weeks(7). Benzidine is rapidly oxidized by Fe(III) and other cations which are frequently found in soils and clay(8).

AQUATIC FATE: Based on a classification scheme(1), Koc values of benzidine adsorbed to 3 estuarine sediments in the range of 462-4,899(2), indicate that benzidine is expected to adsorb to suspended solids and sediment(SRC). Benzidine is a weak base with 2 amine functional groups with pKa values of 4.3 and 3.3(3). These values indicate that benzidine can partially exist in the protonated form under acidic conditions(SRC). Volatilization of the free base from water surfaces is not expected(4) based upon an estimated Henry's Law constant of 5.2X10-11 atm-cu m/mole(SRC), developed using a fragment constant estimation method(5). The conjugate acid will not volatilize since cations are non-volatile(SRC). According to a classification scheme(6), BCF values of 40 and 55 measured in fish(7,8), suggest bioconcentration in aquatic organisms is moderate(SRC). When aerated solutions of benzidine (100 ppb) were exposed to light from a xenon lamp (300-400 nm), complete degradation was observed in 12 hrs(9). Benzidine is rapidly oxidized by Fe(III) and other cations which are frequently found in environmental waters(10). Aqueous solutions of benzidine (0.01%) were reported to be stable for 9 weeks to degradation by soil/river water inoculum(11).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), benzidine, which has an estimated vapor pressure of 7X10-7 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 benzidine 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 2 hours(SRC), calculated from its rate constant of 1.5X10-10 cu cm/molecule-sec at 25 °C(SRC) determined using a structure estimation method(3). Benzidine also absorbs light greater than 290 nm and may undergo direct photolysis(4). Over 40% photodegradation was observed when benzidine adsorbed to silica gel plates was irradiated with UV light > 290 nm for 17 hours(5). Particulate- phase benzidine may be removed from the air by wet and dry deposition(SRC).

At concentrations of 60 to 120 mg/l, benzidine inhibited the oxygen uptake of sludge that had been acclimated to aniline; at concentrations of 40 to 80 mg/l, the oxygen uptake of unacclimated sludge was also inhibited. At ug/l concentrations, however, benzidine was partially degraded.

Although early investigators reported that benzidine was not degradable(1), its resistance to biodegradation was probably due to its toxicity to microorganisms at the high concentrations used. No mineralization occurred when 0.05 ppm of benzidine was incubated for 5 days with activated sludge(6). Several workers report almost complete degradation in simulated treatment plants using activated sludge or sewage inoculum in a few weeks although the percent removal falls off at higher concentrations(2-4). Part of the degradation is due to air oxidation(2). There are conflicting data over the need for acclimation of microorganisms(2-4). A 0.01% solution of benzidine was reported to be stable for 9 weeks to degradation by a soil /river water inoculum(5). In Drummer silty clay loam, benzidine applied at a concn of 10 ppb was degraded 79% after 4 weeks(9). When applied to a silt loam soil (pH 5.4) and incubated for 45 days, 3.3% of the benzidine was mineralized(8). After 365 days, 8.13-11.6% of benzidine had mineralized in 4 soils at pH 5.2-7.8(8). Amending the soil with glucose or alfalfa forage had no affect on the decomposition rate(8). The low decomposition rate compared with that in simulated treatment plants suggests that degradation may be controlled by the soil environment or adsorption to soil(8). However, when benzidine in sludge was applied to a sandy loam soil in a biological soil reactor and worked into the top 20 cm of soil, 42% degraded in 48 days and 55% degraded in 97 days(7). The overall half-life was 76 days(7).

The rate constant for the vapor-phase reaction of benzidine with photochemically-produced hydroxyl radicals has been estimated as 1.5X10-10 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 2 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Benzidine absorbs light greater than 290 nm and therefore, may undergo direct photolysis(2). Over 40% photodegradation was observed when benzidine adsorbed to silica gel plates was irradiated with UV light > 290 nm for 17 hours(3). When aerated solutions of benzidine (100 ppb) were exposed to a light from a xenon lamp (300-400 nm) complete degradation of benzidine was observed in 12 hours(4). Benzidine is very rapidly oxidized by Fe(III) and several other cations which are frequently found in environmental waters, complexes of fulvic acids and in clay minerals(5). Benzidine is a weak base with pKa values of 4.3 and 3.3(2,6), which indicate that under acidic conditions, benzidine will partially exist in the protonated form(SRC). Benzidine is not expected to undergo hydrolysis due to a lack of hydrolyzable functional groups(7).

In a 42 day experiment in a flow-through tank in which bluegills were exposed to 14C-benzidine, the BCF was 40 in the edible portion of the fish(1). The depuration half-life of the 14C-residues was about 7 days(1). After 3 days in a model ecosystem, the BCF for fish, mosquitos, snail and algae were 55, 457, 646 and 1,585(2). Based on a classification scheme(3), the BCF values of benzidine in fish suggests bioconcentration in aquatic organisms is moderate(SRC).

Benzidine exists as a neutral molecule, and as a singly and doubly ionized cation under acidic conditions (acid dissociation constants pKa1 and pKa2 are 4.3 and 3.3, respectively)(1,9) and adsorption to soil is sensitive to the soil pH. In a study of the adsorption of benzidine to 14 soils and sediments, it was found that the Freundlich adsorption constant was not correlated with any soil property such as % organic carbon but rather with pH(1). The pH controls the amount of benzidine in the ionized form and sorption increases as the pH decreases, that is, as a greater fraction of the total benzidine occurs in the ionic form. The Freundlich adsorption constant for the 14 soils and sediments ranged from 50 to 3,940 on a molar basis. The adsorption curve is highly non-linear with the average value of 1/n in the Freundlich adsorption equation being 0.5(1). In another study with 4 soils, the Freundlich adsorption constants ranged from 7,600 to 21,000 and the mean 1/n was 0.768(6). Even though the adsorption curves were not linear, Koc values were estimated to range from 227,000 to 882,000(6). Koc values for benzidine adsorbed to 3 estuarine sediments containing 0.93, 1.36, and 3.01% organic carbon were 4,899, 462, and 3,307, respectively(4). For adsorption to Chesapeake Bay sediment, the Freundlich adsorption constant was 6,025 and 1/n was 0.75 at pH 7.9(5). Adsorption increased as pH decreased, indicating that the protonated form of benzidine is more strongly bound to colloids than the neutral form(5). A sequential extraction procedure was used to show that benzidine binds to soil in two phases(7). Initially a reversible equilibrium is established followed by covalent bonding to soil organic matter, primarily humic acids(7). The benzidine concentration in soil solution decreases rapidly over the first 6 hours and then more slowly(8). After 48 hrs the level of benzidine in soil solution remains constant, 6-22 ppb for soil application rates of 30-50 ppm(8). Benzidine adsorbs to clay minerals forming a blue-colored species, the adsorption increasing with decreasing pH(2). Aromatic amines like benzidine are known to form covalent bonds with humic materials, adding to quinone-like structures followed by a slow oxidation(3,9). According to a classification scheme(10), the Koc values from sediment and soil(4,6) suggest that benzidine is expected to have very low or no mobility in soil(SRC).

Benzidine is a weak base with 2 amine functional groups having pKa values of 4.3 and 3.3(1). These values indicate that benzidine can partially exist in the protonated form under acidic conditions and cations do not volatilize from moist soil or water surfaces(SRC). The Henry's Law constant for the neutral species (free base) of benzidine is estimated as 5.2X10-11 atm-cu m/mole(SRC) using a fragment constant estimation method(2). This Henry's Law constant indicates that the free base is expected to be essentially nonvolatile from water and moist soil surfaces(3). Benzidine is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 7X10-7 mm Hg (SRC), determined from a fragment constant method(4).

SURFACE WATER: Benzidine is rarely detected in ambient water(1). Benzidine was detected in only 1 of 879 water samples in the US as reported in the STORET database(1). In 1990, benzidine was detected at max concns of 240 ug/l (on-site) and 19 ug/ (off-site) in groundwater of a former dye manufacturing facility in Ashland, MA(1).

SURFACE WATER: Benzidine concentrations were as follows: Buffalo River, Buffalo, NY - upstream and downstream of Allied Chemical plant where benzidine was believed to have been discharged (42 samples from 7 sites) -not detected(1). Niagara River near intake of Tonawanda water treatment plant -not detected(1). Sumida River, Japan-site of several dye and pigment plants -concentration of aromatic amines including benzidine 0.21-0.56 ppm(2). Rhine River-detected, not quantified(3). Benzidine was specifically looked for but not found in Lake Erie or Lake Michigan(4).

Maximum concentration in wastewater from foundries 10 ppb; Wastewater from nonferrous metals manufacture 1.2 ppb avg, 6.0 ppb max(1). Detected in oil refinery, municiple and industrial effluents(2). Effluents from textile factories using benzidine-based dyes 3.5 ppb avg; leather factory 0.25 ppb; manufacturing plant using benzidine dyes 3.5 ppb(2). In a comprehensive survey of wastewater from 4000 industrial and publicly owned treatment works (POTWs) sponsored by the Effluent Guidelines Division of the USEPA, benzidine was identified in 1 discharge of the auto and other laundries industry, 70.0 ppb, and two discharges from an unidentified industry, 215.1 ppb mean(3). Of the 1235 stations reporting benzidine in effluents in EPA's STORET database, 1.1% contained detectable levels of the chemical(4).

The author analyzed the water of the Sumida River in Tokyo during 1964. ... Colorimetric analysis revealed that total aromatic amine content of the water (including benzidine) reached levels up to 0.562 mg/l.

High levels of benzidine (up to 2.5 mg/l) were found after analysis of purge wells and seepage water near a waste disposal lagoon receiving dichlorobenzidine-manufacture wastes.

Buffalo River watershed-not detected in 21 samples from 7 sites upstream and downstream from Allied Chemical plant where benzidine was believed to have been discharged(1). Benzidene was not detected in 3240 sediment/soil samples contained in the EPA STORET database(2).

Benzidene was not detected in 110 stations reporting biota levels in the EPA STORET database(1).

Benzidine-based dyes produced in the US and other countries were found to contain < 1-1254 ppm benzidine(1).

Processes in which dried dye is handled have the greatest potential for employee exposure during the manufacture or repackaging of benzidine-based dyes. ... During use of benzidine-based dyes, the greatest potential for exposure would be expected to be among dye-weighers who handle dry powders. /Benzidine-based dyes/

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number U021, 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. A potential candidate for fluidized bed incineration at a temperature range of 450 to 980 °C and residence times of seconds for liquids and gases, and longer for solids.

The following wastewater treatment technologies have been investigated for benzidine: Concentration process: Biological treatment.

This compound should be susceptible to removal from waste water by air stripping.

For more Disposal Methods (Complete) data for BENZIDINE (12 total), please visit the HSDB record page.

/GUIDE 153: SUBSTANCES - TOXIC and/or CORROSIVE (Combustible)/ Fire or Explosion: Combustible material: may burn but does not ignite readily. When heated, vapors may form explosive mixtures with air: indoors, outdoors and sewers explosion hazards. Those substances designated with a (P) may polymerize explosively when heated or involved in a fire. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. Runoff may pollute waterways. Substance may be transported in a molten form.

/GUIDE 153: SUBSTANCES - TOXIC and/or CORROSIVE (Combustible)/ Health: TOXIC; inhalation, ingestion or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.

/GUIDE 153: SUBSTANCES - TOXIC and/or CORROSIVE (Combustible)/ Public Safety: CALL Emergency Response Telephone Number on Shipping Paper first. If Shipping Paper not available or no answer, refer to appropriate telephone number listed on the inside back cover. As an 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. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. Ventilate enclosed areas.

/GUIDE 153: SUBSTANCES - TOXIC and/or CORROSIVE (Combustible)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing provides limited protection in fire situations ONLY; it is not effective in spill situations where direct contact with the substance is possible.

For more DOT Emergency Guidelines (Complete) data for BENZIDINE (8 total), please visit the HSDB record page.

UN 1885; Benzidine

IMO 6.1; Benzidine

49 215 03; Benzidine

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./

The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.

The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.

Unbreakable packaging. Put breakable packaging into closed unbreakable container. Do not transport with food and feedstuffs.

Symbol: T, N; R: 45-22-50/53; S: 53-45-60-61; Note: E

UN Hazard Class: 6.1; UN Pack Group: II