Agent Name
CAS Number
Major Category
Nitrogen Compounds
Benzidine formula graphical representation
1,1'-Biphenyl)-4,4'-diamine; 4,4'-Bianiline; 4,4'-Biphenyldiamine; 4,4'-Biphenylenediamine; 4,4'-Diamino-1,1'-biphenyl; 4,4'-Diaminobiphenyl; 4,4'-Diaminodiphenyl; 4,4'-Diphenylenediamine; Benzidine base; Benzioine; Biphenyl, 4,4'-diamino-; C.I. 37225; C.I. Azoic Diazo Component 112; CI 37225; CI Azoic diazo component 112; Fast Corinth Base B; p,p'-Diaminobiphenyl; p,p'-Dianiline; p,p-Bianiline; p-Benzidine; p-Diaminodiphenyl; [ChemIDplus] UN1885
Benzidine and Derivatives
Grayish-yellow, reddish-gray, or white crystalline powder. Note: Darkens on exposure to air and light; [NIOSH]
"Benzidine is no longer produced for commercial sale in the United States. In 1973, OSHA regulations effectively banned United States production of benzidine. Any benzidine production must be for captive consumption (in-house use), and it must be maintained in closed systems under stringent workplace controls. . . . The predominant use of benzidine is in the production of dyes, especially azo dyes in the leather, textile, and paper industries. The Color Index lists over 300 colors of benzidine-derived dyes, some 18 of which were found to be commercially available in the United States (AATCC 1984; Gregory 1984). Eleven of these 18 dyes were domestically manufactured. Some of these dyes, especially direct browns, greens, and blacks, were available as consumer products in the 1970s (Jenkins 1978). . . . Access to such dyestuffs for home use is no longer available . . ." [ATSDR ToxProfiles]
Caused bladder cancer to workers in the past; both the inhalation and skin routes are significant; [ACGIH]; A liver toxin and carcinogen in experimental animals; health effects after acute exposure in the workplace have not been reported; [NIOSH Guidelines for Chemical Hazards] May cause methemoglobinemia; [HSDB] Known human carcinogen, including dyes metabolized to benzidine; [IARC]
Not produced for commercial sale in the United States since 1974; however, benzidine can be imported and small amounts are still used to make benzidine-based dyes; [ACGIH] See 29CFR1910.1003;
Biomedical References

Exposure Assessment

Skin Designation (ACGIH)
Vapor Pressure
8.98E-07 mm Hg
Explanatory Notes
Carcinogen--No TLV;
Half Life
No reports found; [TDR, p. 167]
Reference Link #2

Adverse Effects

MetHgb is secondary toxic effect
Hepatoxic (a) from occupational exposure (secondary effect) or (b) in animal studies or in humans after ingestion
IARC Carcinogen
NTP Carcinogen
Human carcinogen
ACGIH Carcinogen
Confirmed Human

Diseases, Processes, and Activities Linked to This Agent


Occupational diseases associated with exposure to this agent: