On February 2, 1923, the first leaded gasoline was sold in Dayton, Ohio.

Thomas Midgley, a chemist, worked with Charles Kettering at General Motors Research Corporation. Kettering had modified an internal combustion engine to produce greater horsepower, but it resulted in “engine knocking.” Midgley added tetraethyl lead to the fuel, which eliminated the problem. Kettering named the mixture “ethyl gas” and they first sold it at a station owned by Kettering’s friend, Willard Talbott. The gas was a success.

Unfortunately, leaded gas was toxic to humans and the environment. Workers in plants producing the gas were exposed to lead poisoning. Many died and others went mad. The gas was eventually phased out in the 1970s when the federal standards became stricter.