Legal Definition
A hazardous substance is a chemical or biological agent that poses a significant risk to human health or the environment, requiring specific regulatory control under U.S. law. This term refers to any material capable of causing harm, often necessitating strict testing, labeling, and disposal requirements.
Plain-English Translation
Imagine something in science class that is dangerous—like a chemical or a germ that can hurt people or the planet. It's a substance that needs special rules because it might cause problems if it gets into the body or the environment.