One Man Invented Two of the Deadliest Substances of the 20th Century

Thomas Midgley Jr.’s inventions have had an outsize impact—not all of it good—on humankind

The unassuming face of one of twentieth-century America's most dangerous men, even to himself Library of Congress

Thomas Midgely Jr. had, in the words of author Bill Bryson, “an instinct for the regrettable that was almost uncanny.”  

He is single-handedly responsible for creating two of the most destructive compounds in American history. First, as a chemical engineer for General Motors, Midgley discovered that the addition of tetraethyl lead to gasoline solved the problem of engine “knocking.” The discovery gave Midgley severe lead poisoning, as Smithsonian has written about previously, and made GM millions of dollars while substantially damaging the environment and the American public.

Midgley rose to prominence because of the leaded-gas business, becoming vice president of the new Ethyl Gasoline Corporation. It was then, “buoyed by the success of leaded gasoline,” writes Bryson, that he moved on to “another technological problem of the age.” Bryson writes:

Refrigerators in the 1920s were often appallingly risky because they used dangerous gases that sometimes leaked. One leak from a refrigerator at a hospital in Cleveland, Ohio, in 1929 killed more than a hundred people. Midley set out to create a gas that was stable, nonflammable, noncorrosive and safe to breathe.

Just three days later, he’d come up with a solution, writes Encyclopedia Britannica: dichlorodifluoromethane, a chlorofluorocarbon, or CFC, commercially known as freon. Unlike compounds such as ammonia, butane (yes, really) and sulphur dioxide, freon could be breathed by people and wasn't flammable. Midgley, who was also known for being a show-off, demonstrated the utility of his invention to the American Chemical Society at its annual meeting in 1930, writes Jonathan Edwards for the Royal Society of Chemistry.  He “inhaled a large amount of the gas, and then blew out a candle flame, showing it to be non-toxic and non-flammable.”

Like his earlier invention, chemical manufacturing giants immediately hopped on the freon wagon. “Midgley was again hailed as a hero,” Edwards writes, “being awarded the prestigious Priestley Medal in 1941 and appointed president of the American Chemical Society.”

Later on, of course, it was discovered “that CFCs released by aerosols and damaged fridges were causing serious damage to the ozone layer.”

These weren’t the only things Midgely invented. According to the Inventors’ Hall of Fame (of which he is also an inductee), the scientist—who originally trained as an engineer—held a total of 117 patents, many of which didn’t kill anybody.

But one of his inventions, in the end, did have a personal impact on Midgely: it killed him. Later in life, he was struck by polio, writes Encyclopedia Britannica, and lost the use of his legs. Being of an inquiring mind, he invented a hoist mechanism to help him get in and out of bed. He died when he became tangled in the ropes and the device strangled him.

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