# NIOSH Pocket Guide to Chemical Hazards
o-Tolidine | CAS 119-93-7
C14H16N2 | RTECS DD1225000
Synonyms & Trade Names 4,4'-Diamino-3,3'-dimethylbiphenyl; Diaminoditolyl; 3,3'-Dimethylbenzidine; 3,3'-Dimethyl-4,4'-diphenyldiamine; 3,3'-Tolidine | DOT ID & Guide
Exposure Limits | NIOSH REL: Ca C 0.02 mg/m3 [60-minute] [skin] See Appendix A See Appendix C
OSHA PEL: See Appendix C
IDLH Ca [N.D.] | Conversion
Physical Description White to reddish crystals or powder. [Note: Darkens on exposure to air. Often used in paste or wet cake form. Used as a basis for many dyes.]
MW: 212.3 | BP: 572°F | MLT: 264°F | Sol: 0.1%
VP: ? | IP: ? |  | Sp.Gr: ?
Fl.P: ? | UEL: ? | LEL: ? |
Combustible Solid
Incompatibilities & Reactivities Strong oxidizers
Measurement Methods NIOSH 5013; OSHA 71
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 flush 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 (gas mask) with a chin-style, front- or back-mounted organic vapor canister having 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 Irritation eyes, nose; in animals: liver, kidney damage; [potential occupational carcinogen]
Target Organs Eyes, respiratory system, liver, kidneys Cancer Site [in animals: liver, bladder & mammary gland tumors]
See also: INTRODUCTION