History

First discovered to be useful as an antiknock agent in gasoline by chemist Thomas Midgley, Jr., in 1921

First used on an industrial scale by General Motors Corporation, the DuPont Company, and the Standard Oil Company 

Became standard antiknock agent in gasoline

Accumulated reports of harmful lead poisoning and the harms of lead to the environment by geochemist Clair Patterson in the 1960s and pediatrician Herbert Needleman in the 1970s, among others.

Phased out by the EPA in 1972 because of its environmental harms.

Was found in some gasoline until 1995 at which point leaded gasoline became completely unavailable.