the idea that any one individual has made a significant contribution to the parlous state of the world’s environment seems unlikely

The threats to our environment – global warming, environmental pollution, and so on – seem so huge and widespread that the idea that any one individual has made a significant contribution to the parlous state of the world’s environment seems unlikely. Nevertheless, one man, an American inventor, was responsible for two of the most insidious contributions to the global environment – lead in petrol and the refrigerant freon.

Thomas Midgely Jr suggested the use of lead as an additive to petrol in order to prevent a problem known as “knocking” whereby the fuel would burn too early in the internal combustion cycle and lead to noise and engine damage. Even at the time of the discovery, lead was known to be harmful to humans. After a few years working with the additive, Midgely himself suffered the ill effects of his invention and developed lead poisoning. This was only a minor setback. In spite of his own experience and the death of ten workers at the manufacturing plant, along with hallucinations and insanity in others, Midgely tried to reassure people by pouring the additive over his hands and breathing it in. He claimed that he could do this every day without harming himself, but there is no evidence that it became part of his daily routine.

His next service to mankind was to devise a compound of various atoms – chlorine, fluorine and carbon – as a replacement for substances used in refrigerators at the time which were highly toxic to humans if they leaked out. Freon, also, called dichlorodifluoromethane, was seen as a miracle compound. It was colourless, odourless, non-flammable, non-corrosive and seemed generally a harmless fluid that would sit quietly in your refrigerator changing from liquid to gas and back again as it circulated through the system and kept your food cool.

Within a few years of being introduced, freon was the standard coolant for domestic refrigerators. As seemed customary with his more noxious inventions, Midgely conducted a public demonstration of freon’s low toxicity and generally benign nature by inhaling a lungful of the gas and breathing it out on to a candle flame, which was thereby extinguished.

the lead in petrol and then freon were found to have had disastrous effects on the environment

Both of Midgely’s inventions made fortunes for the companies that manufactured and marketed them, and dominated the field for decades. But first the lead in petrol and then freon and similar refrigerants were found to have had disastrous effects on the environment. Lead in the atmosphere released by car exhausts entered the blood and caused neurological damage in children; the chemicals released from discarded refrigerators made a major contribution to the hole in the Earth’s ozone layer.


But Midgely was long dead by the time the harm caused by his inventions was realized.