Summary
Highlights
Freon found other applications, becoming a propellant in aerosol cans for products like hairspray, bug spray, and paint. Its ability to turn from liquid to gas under changing pressure allowed for continuous sprays. The electronics industry also embraced Freon as a solvent to clean circuit boards before soldering, quickly dissolving grease and impurities without leaving residue, and then rapidly evaporating into the atmosphere.
In the 1930s, DuPont chemists invented Freon, a substance needed for refrigeration. To achieve the desired evaporation and condensation temperatures, they modified methane (CH4) by replacing hydrogen atoms with heavier halogen atoms like fluorine and chlorine. This created chlorofluorocarbons (CFCs), which allowed for precise control over the substance's properties. Freon was a brand name for these CFCs.
Freon was considered a 'miracle substance' due to its colorless, odorless, non-toxic, non-flammable, and incredibly stable nature. These properties made it ideal for refrigerators, enabling widespread domestic use and the birth of a new industry. Air conditioning also adopted the same technology, using Freon as a refrigerant in evaporation coils and compressors.
In the early 1970s, UC Irvine chemists published research warning that Freon destroys ozone, posing a future threat to the protective ozone layer. The mechanism involves UV radiation breaking a chlorine atom off the Freon molecule. This reactive chlorine atom then repeatedly pulls oxygen atoms from ozone molecules, converting ozone (O3) into oxygen (O2) and allowing the chlorine atom to continue the destructive cycle, with one chlorine atom capable of destroying up to 100,000 ozone molecules.
DuPont initially reacted negatively to the findings, attempting to have the chemists fired and launching a smear campaign to discredit them. However, this opposition backfired, prompting other scientists to investigate, which further confirmed the problem. Despite industry resistance, scientific evidence of ozone depletion continued to mount throughout the 1980s.
Ozone depletion leads to increased ultraviolet radiation reaching Earth's surface. For humans, this results in sunburns, skin cancers, eye damage (catalining cataracts), immune system damage, and accelerated skin aging. Animals also suffer similar effects, including sores and lesions on whales. Critically, ocean plankton, which form the base of the marine food web, are being damaged, threatening a collapse of the ocean's nutrition system. Agricultural crops also experience 'sunburn damage,' leading to stunted growth and potential food shortages, underscoring the severity of ozone depletion.
Freon, a completely man-made substance, was invented around 1930. The problem of ozone depletion was identified in the 1970s, but industry opposition delayed action for nearly a decade. By 1987, facing overwhelming scientific evidence and the growing public awareness of the issue, industry ultimately conceded. This led to a crucial international meeting in Montreal, Canada, to address substances depleting the ozone layer, with Freon being the primary concern.