Diphenylhydrazine is a man-made chemical that occurs in two
isomeric forms: 1,1-diphenylhydrazine and 1,2-diphenylhdrazine.
Diphenylhydrazine is produced by the reduction of
nitrobenzene. Little or no information is available for
1,1-diphenylhydrazine. Most toxicological and use data pertain
to 1,2-diphenylhydrazine.