An Uncool Discovery

Freon ad.

Freon ad courtesy of the Hagley Museum and Library.

In modern times, we may occasionally wonder what kind of bugs are growing in an ill-maintained air conditioning system or dirty refrigerator, but we don’t wonder when either of these innocuous appliances is going to explode. 

This wasn’t always the case. Until the 1930s refrigeration and cooling were uncommon, partly because of their high cost, but also because early 20th century refrigerant gases included sulfur dioxide, ammonia gas, propane, butane, and several other compounds that are flammable, poisonous, and otherwise dangerous—especially when pumped through high-pressure tubing in your home or office.

Enter Thomas Midgley Jr., a mechanical engineer, chemist and inventor from Beaver Falls, Pennsylvania. Midgley invented an alternative to toxic explosive refrigerants that was safe to breathe, snuffed flames, and worked more efficiently than its nastier counterparts. His chlorofluorcarbon refrigerants (or CFCs) quickly replaced all other refrigerants. Cooling and refrigeration became safe and less expensive. Or so it was believed.

50 years later researchers realized that CFCs were actually a silent hazard—not to individuals, but to the planet. CFCs soared to the upper atmosphere and lurked there, destroying the ozone layer. Although only a small percentage of CFCs actually made the vertical journey to the upper atmosphere, their effect was devastating. CFCs are a catalyst to the breakdown of ozone. One CFC molecule can catalyze and break down 100,000 ozone molecules.

Despite their danger to the ozone layer, CFCs were in every other way an ideal refrigerant. They aren’t toxic, they don’t burn, and they don’t break down under the stress of years of continuous use. Replacing CFCs was a daunting task for their manufacturers. And none of the replacements used are as effective or versatile as the original CFCs.

In his book Something New Under the Sun, environmental historian J.R. McNeil says Midgley had a greater impact on the environment than any other organism in history. And CFCs are not the only reason. Midgley is also the inventor of tetraethyl lead fuel additives. But that is a subject for a future post.

Episode 28: Summer [Distillations]
Summer Sun
[Periodic Tabloid]

Posted In: History | Technology

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