Famous Scientists

Thomas Midgeley Jr.

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Thomas Midgeley Jr. was a chemist and mechanical engineer who was also one of the most notable names in a group of chemists who developed TEL or tetraethyl lead as well as developed some of the very first chloroflourocarbons. TEL is an additive to gasoline which helped prevent the “knocking” of engines while the CFCs are some of the chemicals still used for cooling purposes. Throughout his life as a scientist, he received more than a hundred patents, but because some of his innovations are now deemed not eco-friendly, his name has been quite tarnished.

Early Life and Background

He hailed from Beaver Falls, Pennsylvania and was born on the 18th of May in 1889. His father was also an inventor and this was one of the reasons why he had been inspired to make his very own innovations. While growing up in Columbus, Ohio, he finished his degree in mechanical engineering from the Cornell University. Despite studying to be an engineer though, his claim to fame had come to him as a chemist instead.


His degree in mechanical engineering wasn’t all lost because the most notable innovations he was known for still related to mechanical engineering to some extent. He worked for Charles F. Kettering at the Dayton Research Laboratories which was under General Motors. They were trying to solve how to avoid knocking in engines, or that continuous pinging or putting sound which was observed in internal-combustion engines.

Midgley was able to deduce that this engine knocking was caused by increased pressure as well as temperature within the cylinders of the engine. Being a mechanical engineer, he could have changed the design of the engine, but it could be said that he “thought out of the box” by solving the problem another way.

He found ways to alter a gasoline’s chemical makeup and this was where he added bromine from seawater and tetraethyl lead. His “no-knock” gasoline was invented in 1921, and naturally, drivers who were constantly experiencing this problem found this as an appealing solution to avoid engine knocking and potential permanent damage to their vehicles. However, there was one major problem from this product—it caused the death of at least 7 workers.

Their deaths had been caused by the lead found in the ethyl gasoline and it had been toxic. The deaths happened in the 1920s and in 1924, Midgely himself took an extended medical leave because of lead poisoning as well. About a year later, he wrote a paper about the hazards of lead poisoning and it was determined how lead additives to gasoline were highly toxic and were also pollutants which caused blood as well as brain disorders in children, some antisocial behavior, and also lowered IQ levels. Come year 1970, the ethyl compounds discovered by Midgely had been removed from gasoline and the negative effects of adding these compounds were widely recognized and ultimately avoided.

Before lead was removed from gasoline to come up with the “no-knock” formulation, the product was called “ethyl” and no mention of lead in its composition was ever mentioned. Automobile manufacturers as well as oil companies even promoted the TEL additive discovered by Midgely as a top additive for ethanol-blend or ethanol fuels. Before Midgely filed for a medical leave caused by lead poisoning, he even received the award for “Use of Anti-Knock Compounds in Motor Fuels” for his Nichols Medal. This award was the his first of many—sadly, this same award was for a product which was later on shunned because of its negative side effects on the environment as well as the health of the people exposed to it.

After his invention of the “no-knock” gasoline, his career continued and in 1928, he was transferred to work for Frigidaire which at that time had also been one of the subsidiaries of General Motors. During his time there, he was then tasked to find safer and more affordable refrigerant substitutes. However, all of those he discovered were either flammable, toxic, or both at the same time. Because of these limitations, he came up with dichlorodifluoromethane which is a mixture of mostly chlorine, carbon, and fluorine—this mixture is now known as the CFCs or chlorofrlourocarbons. The trademark given for this product was “Freon” and it is still being used for some refrigerators, air conditioners, and even insect repellents.

A few decades later, however, a number of studies showed how this same product has been causing the destruction of the ozone layer which in turn reduced the natural protection that humans have against the harmful sun rays. Also of note was that Freon leaks can cause higher death rates in an area caused by asphyxiation since its molecular structure has the ability to displace oxygen. During the year 1980, most products using Freon were banned. What is interesting is that before all of these negative effects were noted, Midgely even wrote one of his papers in 1939 which suggested how the ozone layer could possibly be manipulated with the aim to control climate.

Life After His Inventions

The American Chemical Society even gave Midgely their Priestly Medal which was their highest form of recognition. He also received the Willard Gibbs Award and was later on also elected as the chairman and president of the American Chemical Society.

Later in his life, he had polio which continued to progress and left him in the confines of his home. Even then, he was able to design a system of pulleys to allow him to move from one place to another without the need to be assisted by another person.

Like his several other inventions though, this ambulatory aid he made for himself also had its own dangers. On the second day of November 1944, he slipped and accidentally got himself entangled in the device’s ropes which in turn strangled him to death. He was 55 when this happened. He died thirty years before the negative effects of CFCs were noted along with the other negative effects of lead in gasoline which also caused atmospheric damage.

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