# NIOSH Pocket Guide to Chemical Hazards
o-Dianisidine | CAS 119-90-4
(NH2C6H3OCH3)2 | RTECS DD0875000
Synonyms & Trade Names Dianisidine; 3,3'-Dianisidine; 3,3'-Dimethoxybenzidine | DOT ID & Guide
Exposure Limits | NIOSH REL: Ca See Appendix A See Appendix C
OSHA PEL: See Appendix C
IDLH Ca [N.D.] | Conversion
Physical Description Colorless crystals that turn a violet color on standing. [Note: Used as a basis for many dyes.]
MW: 244.3 | BP: ? | MLT: 279°F | Sol: Insoluble
VP: ? | IP: ? |  | Sp.Gr: ?
Fl.P: 403°F | UEL: ? | LEL: ? |
Combustible Solid
Incompatibilities & Reactivities 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 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 (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 skin; in animals: kidney, liver damage; thyroid, spleen changes; [potential occupational carcinogen]
Target Organs Skin, kidneys, liver, thyroid, liver Cancer Site [in animals: bladder, liver, stomach & mammary gland tumors]
See also: INTRODUCTION