Hazmat is a short official word for hazardous materials: stuff that can hurt people, animals, or the land if it spills, burns, or is breathed in — strong chemicals, gases, some waste. You see HAZMAT on warning signs, on special trucks, and on the heavy suits firefighters wear after a leak. It names the dangerous substances themselves, and people also stretch it to the job of handling them (a hazmat team). It is workplace and emergency language, not a word for ordinary household dirt.

危害物質