Hazardous materials are substances with dangerous ingredients — particular chemicals that can hurt the environment, cause injury, or even death. With due caution, they can be safely used in laboratory instruction, industry, agriculture, medicine, and research. But if misused and released, they can be very harmful — poisonous, flammable, combustible, explosive, corrosive, or radioactive.
There are hundreds of thousands of such products, bought and sold, stored and used in millions of facilities and in transit on American highways, railroads, waterways, and pipelines. Reported releases most often result from transportation and industrial accidents.
Students and ordinary citizens also stock cupboards with diverse household chemicals, many of which are hazardous. Considered collectively, they represent a massive storehouse. Sooner or later hazardous releases are bound to occur. In fact, they happen all the time. Most victims of chemical accidents in the U.S. are injured, not in factories, but at home, and ignorance or carelessness is the cause.