Life-changing chemistry

Which chemist’s work has touched the most lives? Marie Curie? Louis Pasteur? Joseph Lister? Our minds are drawn to the heroic inventors of medicines and the pioneers of bacterial understanding. 

Now enter Thomas Midgley, Jr (1889-1944). An engineering graduate from Cornell University, US, Midgley worked for Dayton Research Laboratories (of General Motors) for 10 years under Charles Kettering, inventor of the electric starter motor, working on the phenomenon of ’knocking’, or incorrect fuel detonation in an engine. He discovered that a little iodine fuel additive would reduce the effect. After a trial-and-error run through hundreds of compounds of 20 elements, the best possible candidate was found to eliminate knocking completely in 1921: tetraethyl lead (TEL) or simply ’ethyl’. Leaded petrol was born.

The dangers of lead poisoning were little understood. Ten people died in the first two years’ operation of the two TEL plants. The public image of TEL was severely shaken, to the point where Midgley held a press conference where he poured the chemical over his hands, and inhaled deeply of it for a full minute. Still, it was only 25 years after Midgley’s death that lead pollution was recognised as a serious concern, and leaded petrol was subsequently banned in many countries. Midgley’s scientific legacy was lost to the world. Or was it?

General Motors required more of Midgley after this landmark discovery. After a few embarrassingly ineffective years as vice president of the newly formed General Motors Chemical Company, he was relieved due to inexperience in organisational matters. He was instead charged with discovering a safe refrigerant for household use - the commonly used refrigerants were ammonia, methyl chloride or sulfur dioxide, all corrosive and toxic, or butane, which is highly flammable. Midgley rolled up his sleeves and examined many candidate oxides, sulfides, nitrides and the like, assessing each for toxicity, flammability and corrosiveness. Fluorine gave fairly ideal properties. Only three days after being given the task, Midgley proudly presented dichlorodifluoromethane, the first ever chlorofluorocarbon or CFC. 

Freon was announced to the world at the annual meeting of the American Chemical Society in 1930. In another astonishing demonstration Midgley inhaled a large amount of the gas, and then blew out a candle flame, showing it to be non-toxic and non-flammable. GM and the DuPont Company promptly agreed to manufacture together the new wonder-gas, branding it Freon, saving GM’s failing refrigerant partner Frigidaire from financial disaster. Midgley was again hailed as a hero, being awarded the prestigious Priestley Medal in 1941 and appointed president of the American Chemical Society. Years later it was discovered, of course, that CFCs released by aerosols and damaged fridges were causing serious damage to the ozone layer. 

Midgley spent the last few years of his life crippled with polio. He was released from his role as vice president of Kinetic Chemicals - GM and DuPont’s Freon-producing company - when his research became unprofitable. Wishing to remain active, he devised a system of ropes and pulleys to allow him to get in and out of bed: his last invention. On the 2nd of November, 1944, he became entangled in the ropes and was strangled to death, aged 55. 

So passed the inventor Thomas Midgley, Jr, hero of the automotive and refrigerant industries for many years. Although his legacy, from a modern point of view, is stained with being by far the largest personal contributor to health and environmental damage, we should still remember him for being a pioneer with his heart in the right place.

Jonathan Edwards