# NIOSH Pocket Guide to Chemical Hazards
3,3'-Dichlorobenzidine (and its salts) | CAS 91-94-1
NH2ClC6H3C6H3ClNH2 | RTECS DD0525000
Synonyms & Trade Names 4,4'-Diamino-3,3'-dichlorobiphenyl; Dichlorobenzidine base; o,o'-Dichlorobenzidine; 3,3'-Dichlorobiphenyl-4,4'-diamine; 3,3'-Dichloro-4,4'-biphenyldiamine; 3,3'-Dichloro-4,4'-diaminobiphenyl | DOT ID & Guide
Exposure Limits | NIOSH REL: Ca See Appendix A
OSHA PEL: [1910.1007] See Appendix B
IDLH Ca [N.D.] | Conversion
Physical Description Gray to purple, crystalline solid.
MW: 253.1 | BP: 788°F | MLT: 271°F | Sol(59°F): 0.07%
VP: ? | IP: ? |  | Sp.Gr: ?
Fl.P: ? | UEL: ? | LEL: ? |
Incompatibilities & Reactivities None reported
Measurement Methods NIOSH 5509; OSHA 65
Personal Protection & Sanitation Skin: Prevent skin contact Eyes: Prevent eye contact Wash skin: When contaminated/Daily Remove: When wet or contaminated Change: Daily Provide: Eyewash, Quick drench | First Aid (See procedures) Eye: Irrigate immediately Skin: Soap wash immediately Breathing: Respiratory support Swallow: Medical attention immediately
Respirator Recommendations NIOSH 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 Escape: (APF = 50) Any air-purifying, full-facepiece respirator with a high-efficiency particulate filter/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, skin absorption, ingestion, skin and/or eye contact
Symptoms Skin sensitization, dermatitis; headache, dizziness; caustic burns; frequent urination, dysuria; hematuria (blood in the urine); gastrointestinal upset; upper respiratory infection; [potential occupational carcinogen]
Target Organs Bladder, liver, lung, skin, gastrointestinal tract Cancer Site [in animals: liver & bladder cancer]
See also: INTRODUCTION