A hazmat suit (hazardous materials suit), also known as decontamination suit, is a piece of personal protective equipment that consists of an impermeable whole-body garment worn as protection against hazardous materials. Such suits are often combined with self-contained breathing apparatus (SCBA) to ensure a supply of breathable air. Hazmat suits are mostly used by firefighters, Emergency Medical Technicians, Paramedics, researchers, personnel responding to toxic spills, specialists cleaning up contaminated facilities, and workers in toxic environments. (source)