# NIOSH Pocket Guide to Chemical Hazards
Benzidine | CAS 92-87-5
NH2C6H4C6H4NH2 | RTECS DC9625000
Synonyms & Trade Names Benzidine-based dyes; 4,4'-Bianiline; 4,4'-Biphenyldiamine; 1,1'-Biphenyl-4,4'-diamine; 4,4'-Diaminobiphenyl; p-Diaminodiphenyl [Note: Benzidine has been used as a basis for many dyes.] | DOT ID & Guide 1885 153
Exposure Limits | NIOSH REL: Ca See Appendix A See Appendix C
OSHA PEL: [1910.1010] See Appendix B See Appendix C
IDLH Ca [N.D.] | Conversion
Physical Description Grayish-yellow, reddish-gray, or white crystalline powder. [Note: Darkens on exposure to air and light.]
MW: 184.3 | BP: 752°F | MLT: 239°F | Sol(54°F): 0.04%
VP: Low | IP: ? |  | Sp.Gr: 1.25
Fl.P: ? | UEL: ? | LEL: ? |
Combustible Solid, but difficult to burn.
Incompatibilities & Reactivities Red fuming nitric acid
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 Hematuria (blood in the urine); secondary anemia from hemolysis; acute cystitis; acute liver disorders; dermatitis; painful, irregular urination; [potential occupational carcinogen]
Target Organs Bladder, skin, kidneys, liver, blood Cancer Site [liver, kidney & bladder cancer]
See also: INTRODUCTION