Lead was introduced into products in the USA by a man named Thomas Midgley, Jr. Originally an engineer, he became interested in industrial applications of chemistry. When working for General Motors Research Corporation in 1921, under the direction of Charles Kettering, he researched a compound called tetraethyl lead. He discovered that using this compound in car engines could reduce engine knock, which happens when the pistons in a car engine knock against each other when they are not properly oiled.
Thomas Midgley Jr.
At this time, lead was known to be dangerous, but that did not stop other industries from using it in their products. Lead was used as a pesticide on fruit, cans of food contained lead, and even tanks of water were lined with lead. It was nearly impossible to find a product that did not contain some amount of lead. Lead was used so extensively in all of these products because of how easy it was to extract and work; these qualities of lead made it an incredibly profitable industry. However, the amount of lead in every-day products could not compare to the large scale and lasting effects of using lead in gasoline.
In 1923, General Motors, Standard Oil of New Jersey, and Du Pont, three of America’s largest corporations, formed a joint company called the Ethyl Gasoline Corporation, or the Ethyl Corporation for short. Their goal was to make and sell as much tetraethyl lead to the world as possible. They renamed the additive ‘tetraethyl lead’ to ‘ethyl’ on the grounds that it sounded better than using the word ‘lead’. Tetraethyl lead was introduced for public consumption in February of 1923.
Sticker labeling gasoline pump for tetraethyl lead
Immediately upon the great success that resulted from the introduction of tetraethyl lead to the public, rumors began to circulate about the dangers of lead. Many workers for the corporations producing lead additives began to become sick, and many died on the job. To stop these rumors and ideas that the lead was the problem, Midgley held a demonstration for reporters. During this demonstration to show that lead was not toxic, he held a beaker of tetraethyl lead to his nose for a minute, and he claimed that he could do the same thing every day with no consequences. Midgley knew this claim was a lie, as he was already ill from overexposure to lead, and he would only go near it when confronting journalists.
After tetraethyl lead had become a success, Midgley turned to other issues. In the 1920s, refrigerators were risky appliances, as they would often leak dangerous gases. To solve this issue, Midgley, Charles Kettering, and Albert Leon Henne began to synthesize a gas that was noncorrosive, stable, nonflammable, and safe to breathe. The gas Midgley invented was a type of chlorofluorocarbons, also known as CFCs. CFCs are organic compounds composed of carbon, chlorine, and fluorine, and they went into production in the 1930s in a variety of products, including refrigerators, aerosols, air conditioners, and solvents. These men had thought that the bond between carbon and fluorine would be stable enough to not release hydrogen fluoride, a deadly gas, into the air, along with other decay products. They also rejected the idea that the gas they synthesized could be toxic, as it was chemically inert. The first CFC they invented was dichlorodifluoromethane, also known today as Freon. In 1937, Midgley received the Perkin Medal from the Society of Chemical Industry for his work with CFCs. He also received two awards from the American Chemical Society: the Priestley Medal in 1941 and the Willard Gibbs Award in 1942. Midgley became president and chairman of the American Chemical Society in 1944. Despite Midgley’s seemingly incredibly successful work, it would later be discovered that CFCs were massively destructive to the Earth’s ozone layer. While CFCs are low in abundance, they are able to capture and destroy thousands of pounds of atmospheric ozone. CFCs are also much more efficient at absorbing heat than carbon dioxide, so they are much more powerful greenhouse gases. Midgley would never learn of the destructive force of chlorofluorocarbons, because he passed away in 1944 at the age of 55.
The effects of these compounds, tetraethyl lead and chlorofluorocarbons, would not be discovered until Clair Patterson, a student at the University of Chicago, began his attempt at determining an age for the Earth.