E.P.A.-banned pesticide

DDT

["\"Insecticide outlawed in the U.S. in '72.\""]

The clue refers to DDT, a powerful pesticide once widely used in the U.S. before the Environmental Protection Agency (E.P.A.) banned it in 1972 due to its harmful effects on wildlife and human health. The abbreviation "E.P.A." in the clue directly points to the agency responsible for the ban, making "DDT" the obvious answer. It’s a straightforward reference—no wordplay, just a historical fact about a notorious chemical.