Professionalism/Thomas Midgely Jr. and the Rise and Fall of Tetraethyl Lead

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Midgely Jr. in the 1930s or 40s

Thomas Midgely, Jr. was an American engineer and inventor born on May 18, 1889, in Beaver Falls, Pennsylvania. He was the son of Thomas Midgley Sr., who was a noted inventor of automobile tires.

Early Life[edit | edit source]

Midgley Jr. was raised in Columbus, Ohio, where he attended the Brett's Academy and later enrolled at Cornell University.[1] During his time at Cornell, Midgley Jr. studied mechanical engineering. His interest in experimentation was so great that he did not have time for many of the usual student activities, although he did at one time organize an aviation club among the students. The club had no airplane, not even a glider, but it was perhaps one of the first such organizations to be formed.[1]

After graduating from Cornell in 1911, Midgley Jr. began his career working for National Cash Register Company in Dayton, Ohio. Later, in 1916, he worked as a research staff with Charles Kettering for the Dayton Engineering Laboratories Company (DELCO). That same year he discovered iodine as a anti-knock fuel additive, but during WWI, his laboratory was devoted to the war effort. After the war, his work to find an anti knocking agent resumed and he discovered tetraethyl lead in 1920.[1]

Career[edit | edit source]

Tetraethyllead[edit | edit source]

Initial Development & Manufacture[edit | edit source]

Many cars in the early 20th century suffered from engine knocking, a potentially destructive effect caused by the poor-quality gasoline of the time. In order to make engines run more smoothly, Charles Kettering, head of General Motors Research, tasked Midgely to come up with an anti-knock fuel additive in 1916. In 1920, Midgley proposed adding ethanol to gasoline, and called it the "fuel of the future."[2] While ethanol was safe and effective at reducing engine knocking, General Motors wanted an additive that they could patent and make profits from, so Midgely spent a few more months looking for alternatives. In December 1921, he proposed adding Tetraethyllead to gasoline instead of ethanol. Tetraethyllead had been discovered in 1853 by a German chemist, and had known harmful effects. It had no commercial applications at the time, but Midgley proposed it knowing that it would be cheap, effective and easily patentable.[3]

Gasoline containing Tetraethyllead was marketed as "Ethyl Gasoline."

General Motors, in cooperation with Standard Oil, created the Ethyl Corporation, with Midgley as vice president.[4] During early production of Tetraethyllead Midgley emphasized efficiency, secrecy, and branding over safety. Tetraethyllead was branded Ethyl internally and externally, implying ethyl alcohol and excluding lead entirely due to its publicly known health risks. Midgley reassured the Public Health Service and the Surgeon General in December 1922 that "[Tetraethyllead’s possible danger] has been given very serious consideration... although no actual experimental data has been taken.”[5] Early 1923, Midgley suffered lead poisoning and spent six weeks in Florida to recover, experiencing "digestive derangements, subnormal body temperatures and reduced blood pressure."[4][5] While in Florida, Midgley wrote an oil industry engineer that Tetraethyllead poisoning the public was "almost impossible, as no one will repeatedly get their hands covered in gasoline containing tetraethyl lead - it stings and burns... The exhaust does not contain enough lead to worry about, but no one knows what legislation might come into existence fostered by competition and fanatical health cranks."[5] In September 1923, General Motors agreed to fund a US Bureau of Mines investigation into the possible dangers of Tetraethyllead, where any potential reports were obligated to "be submitted to [Ethyl Corporation] for comment, criticism, and approval [prior to publication.]"[6]

In April 1924, at a Dayton plant manufacturing Tetraethyllead, two employees died and 60 were sickened from lead poisoning; the deaths were kept secret from the public and internally the workers were blamed for not following procedure.[4][7] Several months later in September 1924, despite knowledge of earlier production deaths, Midgley encouraged dangerous production practices without regard for worker fume ventilation to speed up production.[5]

Late October 1924, five workers died and 35 were sickened at a New Jersey plant manufacturing Tetraethyllead, with workers suffering "severe palsies, tremors, hallucinations, and other serious neurological symptoms of organic lead poisoning." Major newspapers including the New York Times and the New York World reported on the deaths and plant conditions, resulting in immediate public outcry. Midgley publicly blamed the workers, stating "the [workers], regardless of warnings and provision for their protection, had failed to appreciate the dangers of constant absorption of the fluid by their hands and arms."[6] Midgley further sought to reassure the public of Tetraethyllead's safety by washing his hands thoroughly in Tetraethyllead during a press conference, stating "I'm not taking any chance whatever... Nor would I take any chance doing that every day."[7] Also within days of the plant deaths reports, the US Bureau of Mines publicly released a report of preliminary findings regarding the public safety of Tetraethyllead as a fuel additive, which concluded Tetraethyllead was almost certainly completely safe for the public as a fuel additive.[6]

The Public Health Service Tetraethyllead Conference[edit | edit source]

Despite Midgley's, Ethyl Corporation's, and the US Bureau of Mines' assurances of public safety, public outcry persisted with many scientists and labor activists e.g., the Workers' Health Bureau, demanding further investigation into the safety of Tetraethyllead.[6] Within days, Philadelphia, Pittsburgh, and New Jersey would ban production and sale of gasoline containing Tetraethyllead. In a December 1924 private meeting with the Surgeon General, Standard Oil requested the Public Health Service hold a conference on the safety of Tetraethyllead; Ethyl Corporation publicly and voluntarily withdrew its product from market before the May 20, 1925 conference.[7] Midgley testified at the conference that production and distribution of Tetraethyllead was now completely safe, stating "shipping [Tetraethyllead] has never shown any effects whatever of hazard to the people handling it," "we had trouble in the early days from lack of background," and "[Tetraethyllead] becomes dangerous due to carelessness of the men in handling it."[8]

Following the Public Health Service conference, Midgley published in the American Chemical Society's Industrial & Engineering Chemistry Journal that Tetraethyllead is only possibly harmful when manufacturing or handling concentrated Tetraethyllead, and gasoline with Tetraethyllead poses no public health risks. Some excerpts include "After [Ethyl] gasoline has been introduced in the tank of an automobile there are no health hazards, although many imaginary ones have been suggested;" and "The one [possible public health hazard] is the [improper] use of the [Ethyl] gasoline in an open flame for toasting bread, in which case it has been determined that after several days of such a diet a touch of painter’s colic may result."[9]

Within and following the conference, the prevailing sentiment of both the public and public health professionals was that overwhelming evidence of harm must exist before Tetraethyllead is banned as a fuel additive; however, many experts "voiced serious doubts in private," not wanting to go public largely due to personal economic ties to the Ethyl Corporation and wider political/economic considerations e.g., finding Tetraethyllead's risks worth its productivity/efficiency benefits.[6] While the conference did create a special committee to investigate potential public dangers of Tetraethyllead as a fuel additive, limited funding and a tight deadline resulted in a deficient investigation showing no noted harms of Tetraethyllead gasoline with explicit recommendations to pursue further government study, recommendations that were never followed. Following the committee's investigation sales of gasoline with Tetraethyllead were immediately resumed.[7]

Freon[edit | edit source]

The Antarctic Ozone Hole in 2009.

In 1928, Midgely was directed by Charles Kettering, head of General Motors Research, to develop a new refrigerant for General Motors' subsidiary Frigidaire.[10] He discovered dichlorofluoromethane, a chlorofluorocarbon (CFC), which was marketed as Freon starting in 1930.[10][1] Freon had advantages over refrigerants in use at the time since it was nontoxic and nonflammable[10][1][11]; the common refrigerants of the era were ammonia, sulfur dioxide, and methyl chloride, which were noxious and flammable.[10] In addition to being used in refrigeration, Freon and other CFCs were employed in air conditioning, as aerosol propellants, in fire suppression, and in other applications.[12]

CFCs proliferated in the following decades, and there were few serious concerns about any possible environmental impacts that they might have.[11] Although the particles were man-made, it was assumed that they would eventually find some sort of natural "sink" and little thought was given to where the chemicals would eventually end up.[11]

Environmental Impact[edit | edit source]

The environmental impacts of CFCs were first theorized in 1972, when it appeared that there were CFCs present throughout the atmosphere.[11] In 1974, Molina and Rowland published their paper proposing that the primary sink for chlorofluoromethanes was the stratosphere, where they are broken down from UV radiation.[11][13]

Freon and other CFCs are classified as "ozone-depleting substances."[14] These substances are responsible for depletion of the ozone layer, which occurs when UV radiation from the sun frees the chlorine atoms from a CFC molecule.[13] This chlorine reacts with ozone to form chlorine monoxide and oxygen, and the chlorine monoxide is able to react with oxygen radicals to once again become free chlorine.[13][15] Through this process, chlorine atoms from CFCs are able to "destroy over 100,000 ozone molecules before it is removed from the stratosphere."[12] CFCs are principally responsible for the Antarctic ozone hole.[11][12]

Professional and Ethical Perspectives on the Career of Thomas Midgely, Jr.[edit | edit source]

Perspectives of Midgely's life changed dramatically after his death. He was a highly decorated chemist during his lifetime, having received the four "most important" medals for chemical achievement: the Nichols Medal of the New York Section, the Perkin Medal of the Society of Chemical Industry, the Priestly Medal of the American Chemical Society, and the Willard Gibbs Medal of the Chicago Section. He was also on the Board of Directors for the American Chemical Society from 1930 until his death, the chairman of the Board since 1934, and in 1944 was elected president. He also became a member of the National Academy of Sciences in 1942.[1]

In the decades following his death, tetraethyllead was banned from use in gasoline in the US and CFC use was reduced following the Montreal Protocol. Midgely's inventions have gone down in infamy for their widespread destructive impacts on the atmosphere and human health. J.R. McNeil writes "[He] has had more impact on the atmosphere than any other organism in Earth's history."[16] Midgely neglected to study the possible environmental impacts of Freon and other CFCs before allowing them to be brought to market. Professionals owe responsibility not only to their clients, but to society at large, and the failure to consider the long-term impacts of his discovery represents a professional and ethical shortfall on the part of Midgely and his collaborators.

Legacy[edit | edit source]

  1. a b c d e f Kettering, Charles F. (1947). "Biographical Memoir of Thomas Midgely, Jr. 1889-1944" (PDF). Biographical Memoirs of the National Academy of Sciences. 24: 361–380.
  2. Conocimiento, Ventana al (2021-05-12). "Thomas Midgley, The Most Harmful Inventor in History". OpenMind. Retrieved 2023-05-09.
  3. Sutton, Mike (2021-12-20). "Thomas Midgley and the toxic legacy of leaded fuel". Chemistry World. Retrieved 2023-05-09.
  4. a b c Martel, Mark. "How Thomas Midgley, Jr gave cars zoom, homes A/C, saved countless lives, helped win the war and almost doomed us all". Engineers Club of Dayton Foundation.
  5. a b c d ChemCases. "Tetraethyllead - Toxicity". LibreTexts. Kennesaw State University.
  6. a b c d e Rosner, D; Markowitz, G (1985). "A 'gift of God'?: The public health controversy over leaded gasoline during the 1920s". American Journal of Public Health. American Public Health Association. 75 (4): 344–352. doi:10.2105/ajph.75.4.344. ISSN 0090-0036.
  7. a b c d Kitman, Jamie (2000-04-20). "The Secret History of Lead". The Nation. New York City: Katrina vanden Heuvel. ISSN 0027-8378.
  8. "1925 Proceedings of a Conference to Determine Whether or not there is a Public Health Question in the Manufacture, Distribution, or Use of Tetraethyl Lead Gasoline" (PDF). United States Public Health Service. 1925.
  9. Midgley, Thomas (1925). "Tetraethyl Lead Poison Hazards". Industrial & Engineering Chemistry. American Chemical Society (ACS). 17 (8): 827–828. doi:10.1021/ie50188a020. ISSN 0019-7866.
  10. a b c d Giunta, Carmen J. (2006). "Thomas Midgely, Jr., and the Invention of Chlorofluorocarbon Refrigerants: It Ain't Necessarily So" (PDF). Bulletin for the History of Chemistry. 31 (2): 66–74.
  11. a b c d e f McElroy, C.T.; Fogal, P.F. (2008-01-01). "Ozone: From discovery to protection". Atmosphere-Ocean. 46 (1): 1–13. doi:10.3137/ao.460101. ISSN 0705-5900.
  12. a b c US EPA, OAR (2017-06-05). "Basic Ozone Layer Science". Retrieved 2023-04-27.
  13. a b c Molina, Mario J.; Rowland, F. S. (1974). "Stratospheric sink for chlorofluoromethanes: chlorine atom-catalysed destruction of ozone". Nature. Springer Science and Business Media LLC. 249 (5460): 810–812. doi:10.1038/249810a0. ISSN 0028-0836.
  14. US EPA, OAR (2015-07-17). "Ozone-Depleting Substances". Retrieved 2023-04-27.
  15. "Ozone Chapter 5". Retrieved 2023-04-27.
  16. McNeill, John (2001). Something New Under the Sun: An Environmental History of the Twentieth-Century World (1 ed.). New York: W. W. Norton & Company. ISBN 978-0393321838.