Phenylhydrazine appears as pale yellow crystals. Melting point 66°F. Becomes an oily liquid. Toxic by ingestion, inhalation and skin absorption. Flash point 192°F. Autoignition temperature 345°F. Soluble in alcohol.Phenylhydrazine is a phenylhydrazine that is the monophenyl derivative of hydrazine. It has a role as a xenobiotic.