Born on May 18, 1889, in Beaver Falls, Pennsylvania, Thomas Midgley Jr. grew up surrounded by innovation. His father was a tire designer in the automobile industry, and his grandfather an inventor. Midgley graduated in mechanical engineering from Cornell University in 1911 and began his career in Dayton, Ohio, a center of technological advancement.
The Birth of Leaded Gasoline
While working at a General Motors research lab, Midgley was tasked with solving the issue of engine knocking. By 1921, he discovered that adding tetraethyl lead (TEL) to gasoline drastically reduced knocking. Ethylene bromide was also added to prevent lead buildup in engines.
Despite early warnings about lead’s toxicity, General Motors marketed the additive as “Ethyl” to avoid public concern. When workers at TEL production plants began falling ill or dying, Midgley staged a publicity stunt in 1924—pouring TEL on his hands and inhaling its fumes—to downplay the dangers. Ironically, he later suffered from lead poisoning himself.
Revolutionizing Refrigeration—and Damaging the Atmosphere
After recovering, Midgley took on a new challenge: finding a safer alternative to toxic refrigerants like ammonia. In 1930, he helped create chlorofluorocarbons (CFCs), marketed as Freon. CFCs were non-toxic, stable, and widely adopted in refrigeration and aerosol products.
To demonstrate their safety, Midgley again used himself as proof—inhaling Freon and extinguishing a candle during a live presentation. His invention revolutionized home appliances and earned him widespread acclaim.
Tragedy and Death
By the 1940s, Midgley was an internationally celebrated inventor. However, in 1944, polio left him disabled. He designed a pulley system to assist with movement, but tragically, it led to his accidental strangulation and death on November 2, 1944.
A Legacy Reexamined
It wasn’t until decades later that the full impact of Midgley’s inventions came to light. By the 1970s, scientists found dangerously high levels of lead in the environment, with devastating effects on children’s cognitive development and health. The U.S. began phasing out leaded gasoline in the 1980s, but its legacy persists.
Meanwhile, in 1974, researchers Mario Molina and Frank Sherwood Rowland discovered that CFCs were depleting the ozone layer. Their findings led to the 1987 Montreal Protocol, a global agreement to ban ozone-depleting substances. Thanks to international efforts, the ozone layer is now on a slow path to recovery.
A Cautionary Tale
Thomas Midgley Jr. was once seen as a hero of innovation. Yet, his two most influential inventions—leaded gasoline and CFCs—caused untold environmental and public health damage. His story remains a powerful cautionary tale: even well-intentioned innovation, when not fully understood, can lead to catastrophic consequences.
