Thomas Midgley Jr. will go down in history for his inventions, but what is remembered is not the benefits they had, but the planet altering side effects that still impact every human to this day. Midgley’s work was so damaging, that his inventions brought together every single country in an effort to revert their effects. So, who was this man, and how did he become known for being the man who almost destroyed the planet (twice).
Midgley was born in Beaver Falls, Pennsylvania, on May 18, 1889. He came from a family of inventors, with his father working on tires and his maternal grandfather getting patents on a range of improvements he made to tools. Midgley would follow in their footsteps and graduated from Cornell University in 1911 with a degree in mechanical engineering. In 1916, after some years working for the National Cash Register company, as well as for his father in the automobile industry, he gained a position on the research staff of a local engineering laboratory. Three years later this company become a research arm of General Motors. It is here that Midgley made his first major discovery.
Thomas Midgley Jr. himself. Image by shenz2011 on Flickr.
He had been assigned to working on solving the problem of engine knocking, which was hampering the efficiency of engines. At the time it was believed knocking was caused by preignition of the fuel (when the fuel ignites before the spark plug fires, so the piston is still compressing the gas), but Midgley showed that it was a result of an abnormal rise in pressure after ignition. His next task was to go about solving it.
It is useful to note that Midgley, although an engineer by degree, had a broad range of interests, and chemistry would become more prevalent in his work as his life went on. Whilst at school Midgley become infatuated with the periodic table and during his years of chemical research would carry one around with him everywhere, which he claimed was a guide to the discovery of tetraethyl lead as an anti-knock agent.
However, the path to tetraethyl lead as an anti-knock agent, despite being “guided”, was far from direct. Midgley tested practically every substance he could get his hands on, from Iodine to ethanol to melted butter. Many substances solved the knocking issue, but according to Charles F. Kettering (the director of research at General Motors at the time, and Midgley’s boss), “every one had some limitation or shortcoming”. Hence, tetraethyl lead was chosen and adjustments were made to engine designs to prevent the build up of lead, ensuring that the majority of lead produced was pumped out as fumes from the engines exhaust.
Today pumping lead into the atmosphere sounds ill-advised, and unsurprisingly it sounded ill-advised in Midgley’s time as well, with leads dangers having been recognised since ancient Rome. This was likely the reason that the anti-knock compound was marketed as Ethyl, as opposed to including lead in its title. It should be noted that ethanol was tested, had similar anti-knocking properties to tetraethyl lead, and would not have required engine redesign to avoid build up in the engine itself. Researchers are unsure why it was not utilised instead, but the cynics among them point out the relative ease of making ethanol, hence no patent could be obtained on it and its distribution could not be controlled. It seems likely that the highly toxic tetraethyl lead was chosen thanks to it having the potential to be more profitable, despite the risks it posed.
Once manufacture of leaded petrol began the dangers became apparent. Exposure to high doses of lead result in irritability, headache, mental dullness and attention difficulty, memory loss, tremor, and hallucinations, no wonder the Standard Oil lab where it was developed quickly became known as the “Looney Gas Building”, and plants in Ohio and New Jersey (nicknamed “the house of butterflies” as workers kept hallucinating insects) saw multiple fatalities in staff. A century earlier, General Motors had first proposed adding lead to petrol, but the idea was shut down by the scientific community who feared its effects. In the 1920s companies such as General Motors, Standard Oil and the Dupont Corporation, happily looked the other way.
The controversy around leaded petrol at the time pushed Midgley to perform a demonstration on October 30th, 1924, where he washed his hands in a container of tetraethyl lead and inhaled its vapour for sixty seconds. Midgley failed to mention that the previous year, he had taken a long holiday in Miami to recover from lead poisoning, and not long after the demonstration was once again diagnosed with it. Despite this he continued to insist on its safety throughout his life.
It took decades for researchers to finally present data showing the health effects of leaded petrol, likely due to push back from the industries involved in its manufacture. In 1980, Japan became the first country to ban it, but it took until 2021 for the final country, Albania, to follow suit (there is an interactive map showing the phase out over the years). Despite Midgley’s demonstrations and insistence on the safety of Ethyl, it is estimated that the global ban on tetraethyl lead in road vehicle fuel (it is still legal in aviation and marine fuels), prevents 1.2 million premature deaths annually.
A brand of petrol which utilised Ethyl as an anti-knock agent. Image from Leo Reynolds on Flickr.
His other notable invention came about after “solving” the engine knocking issue, he now turned his attention to refrigeration. The industry was in desperate need of a non-flammable and non-toxic refrigerant and Midgley had his periodic table close at hand to guide him once again. This time Midgley concluded that such a refrigerant would have to contain fluorine, and despite being warned of the dangers of working with the gas (Midgley was surely accustomed to controversy at this point), he prepared his candidate, dichlorodifluoromethane, which would be given the name Freon. Freon fit all the briefs, it was non-flammable, non-toxic and an excellent refrigerant, and Midgley demonstrated its safety in the method he knew best, testing it on himself. He inhaled the gas and when exhaling used it to extinguish a candle.
Unlike Ethyl, Freon was not a controversial discovery at the time, in fact it was long after Midgley’s death that its impact would come to light. In 1974, F. Sherwood Rowland and Mario J. Molina theorised that chlorofluorocarbons (CFCs), of which Freon was the first example, were rising into the atmosphere and depleting the ozone layer. This layer of O3 in our atmosphere is vital for blocking the sun’s ultraviolet rays and depletion of it would vastly increase risk of skin cancer, cataracts, and general damage to humans and the environment. Unsurprisingly, industry representatives attempted to discredit these findings, including by complaining that they had used the brand name Freon without permission. In 1976, the National Academies of Science issued a report in support of this theory and, after Congressional hearings came to the same conclusion, bans on CFCs began to be explored, despite opposition from the chemical industry. The evidence that brought an end to CFCs came about in 1985, when the British Antarctic Survey confirmed the presence of a hole in the ozone layer.
At this point Freon and it’s “off-spring” (the other CFCs developed), were in widespread use, in aerosols, packaging and refrigerators, with the worldwide production being approximately one million tons per year. In spite of this, the hole in the ozone layer made the danger tangible and spurred international action. This came in the form of the Montreal Protocol in 1987, where 56 countries agreed to half their CFC production, and in the following years the protocol was widened to a worldwide phaseout of CFCs. The Montreal Protocol is an extremely rare case of a treaty which was universally ratified, with East Timor being the last to do so, in September 2009.
The protocol has been an amazing success, with 98% of ozone depleting substances having been phased out and predictions that the ozone layer will have recovered by the middle of this century. Its effectiveness highlights the impact humanity can have when it comes together to achieve a goal, as without it ozone depletion would have increased tenfold by 2050. It is estimated that by 2030 the protocol will be saving 2 million people a year from skin cancer.
Ozone hole as imaged by NASA in 2015. Image by NASAEarth on Flickr. Interactive map over the years can be found here.
The legacy of Thomas Midgley Jr. does make him one of the most impactful chemists of all time, unfortunately those impacts consist of millions of premature deaths and serious environmental damage. In a tragic twist of fate, his death in 1944 came at the hand of one of his own inventions. Having contracted polio in 1940, he had become wheelchair-bound and thus devised a machine that would lift him from his bed to his wheelchair via strings. On November 2nd, 1944, he became entangled in these strings and died of strangulation.
Midgley’s many lead poisoning diagnoses suggest that he understood the dangers of Ethyl and the choice of tetraethyl lead over ethanol implies Midgley allowed or even pushed for the profitable option to be taken, despite the risk to human life. The impact of Freon was not understood until the 1970s and hence Midgley died with the belief that Freon had revolutionised the refrigeration industry and changed the world for the better.
28th meeting of the parties involved in the Montreal Protocol. Repairing the ozone layer is a collaborative effort that continues today. Image by U.S. Department of State on Flickr.
Midgley’s story bears similarity to many other scientific horror stories, and highlights how corporations fuelled by greed are often in constant opposition to progress and have little regard for human life if profits can be made. In this case, however, it is important to also recognise how the world came together to act, with global bans on both his discoveries now in place. In a time when global issues and tensions are peaking, it serves as a reminder of the strength of humanity when unified under a common mission.
Featured image: Created by Callum Oozeerally, using images by Javier Miranda on unsplash.com, Paul Mercer on Flickr, and shenz2011 on Flickr.