My last blog left Thomas Midgley having solved the engine knock problem by adding leaded gas to the world’s troubles. At the time, lead was a known poison that could lead to all kinds of medical problems, just a few being blindness, kidney failure, and cancer. The EPA estimated in 1985 that five thousand Americans died every year from lead related heart disease.
That problem solved, Midgley turned his attention to refrigerators. Refrigerators for home use had been invented in 1913, and in 1923 Frigidaire came out with the first self-contained unit. But they had one worrisome problem – they tended to explode. The agents used for cooling were sulfur dioxide and ammonia – corrosive and toxic and flammable. If they leaked, which they tended to do, the results were explosive. Midgley started working on it and came up with a combination of chlorine, fluorine and carbon. He called it Freon, and it later became known as CFC. It was non-flammable and non-toxic and non-corrosive. Freon became an immediate success. As well as solving the refrigerator problem, it was used in air conditioners and as a propellant in spray cans.
Midgley was awarded the Priestly Medal by the American Chemical Society in 1941. In his acceptance speech, he stated he was glad his inventions gave citizens such life-improving benefits.
As it turned out, CFCs were even more destructive than lead, but it took fifty years to figure that out as scientists were slowly discovering the effects of CFCs on the atmosphere. In 1985, scientists discovered a large hole in the ozone layer over Antarctica. CFCs were the culprit, and they work more quickly the colder the temperature.
Ozone is tri-atomic oxygen – simply, three atoms of oxygen combined to form a molecule. If breathed in sufficient quantities, it will damage lung tissue. But in the stratosphere, it protects us by blocking solar ultraviolet rays that cause skin cancer.
One kilogram of CFCs can destroy seventy thousand kilograms of ozone. The main culprit is chlorine. It is estimated that a single chlorine atom can destroy 100,000 ozone molecules. And those CFC compounds remain in the atmosphere for a century. Per molecule, CFCs are said to be ten thousand times more powerful than carbon dioxide at worsening the greenhouse effect. CFCs were banned in 1996.
Midgley’s last invention had a sad result. He suffered from polio, which eventually left him crippled, and he invented a series of motorized pulleys to help him get in and out of bed. In 1944, he was strangled to death as he became entangled in his own invention. Some think he committed suicide. Midgley didn’t live to see his two inventions globally banned after having affected every person on the planet for decades. He was a successful, well-intentioned inventor who had no idea of the destruction he would cause.
Sources:
KnowledgeNuts.com Dominic Goland July 19, 2013
Realclearscience.com Ross Pomeroy October 29, 2013