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
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
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]