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
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]