light beige to grey-beige crystalline powder
o-Tolidine dihydrochloride is used as a sensitive colorimetric reagent for gold and for free chlorine in water.
Acidic organic/inorganic salts, such as 3,3'-Dimethylbenzidine dihydrochloride, are generally soluble in water. The resulting solutions contain moderate to high concentrations of hydrogen ions and have pH's of less than 7.0. They react as acids to neutralize bases. These neutralizations generate heat, but less or far less than is generated by neutralization of inorganic acids, inorganic oxoacids, and carboxylic acid. They usually do not react as either oxidizing agents or reducing agents but such behavior is not impossible. Many of these compounds catalyze organic reactions.
Flash point data for 3,3'-Dimethylbenzidine dihydrochloride are not available, but 3,3'-Dimethylbenzidine dihydrochloride is probably combustible.
Suspected carcinogen
with experimental carcinogenic data.
Mutation data reported. When heated to
decomposition it emits very toxic fumes of
HCl and NOx
