NIOSH recommends in this document that workers should not be exposed to benzyl-chloride (100447) concentrations greater than 5.0mg/m3 determined as a ceiling concentration during any 15 minute sampling period. Medical surveillance for workers must include preplacement medical studies, periodic examinations at least annually, counseling of any worker demonstrating any medical condition which could be aggravated by exposure to benzyl-chloride, medical services to exposed workers, and the keeping of medical records. Labeling requirements were listed. Protective clothing should include respiratory protective devices, gloves, gig type aprons, boots, and overshoes. Workers should be instructed as to the hazards associated with benzyl-chloride exposure. Work practices, sanitation and housekeeping requirements were listed. Exposure of humans has resulted in weakness, rapid fatigue, persistent headaches, increased irritability, hot feeling, loss of sleep and appetite, and itching skin. In inhalation studies, laboratory animals demonstrated marked hyperemia of the ears, paws, and tails along with respiratory tract inflammation. Some studies have indicated that benzyl-chloride may be mutagenic and carcinogenic; teratogenic effects had not been reported.