Phenylhydrazine (also known as the hydrazinobenzene) is an industrial substance suspect of carcinogenic potential for humans. Phenylhydrazine was the first hydrazine derivative characterized, reported by Emil Fischer in 1875. Phenyl-hydrazine is used to prepare indoles via the Fischer Indole Synthesis, which are intermediates in the synthesis of various dyes and pharmaceuticals. This molecule is also used to induce acute hemolytic anemia in animal models. Exposure to phenylhydrazine may cause contact dermatitis, hemolytic anemia, and liver damage.