Back in 1988, two Australian scientists, Aslam Khalil and R. A. Rasmussen, used Freon to calibrate the gas exchange on termites in the soil. They ran into problems when the Freon kept disappearing and eventually found the soil microbes were using Freon as a food source. Freon was being decomposed in a matter of days or weeks. Now, it does not take a Ph.D. to figure out that if CFCs are four to eight times heavier than air, many will ultimately meet their demise in the soil by microorganisms. In addition, it is interesting to note that the greatest concentration of CFC-destroying organisms may be present at the surface of the world's oceans.
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Many people may be unaware of both Du Pont and ICI's vested financial interest in the banning of CFCs. These two corporations have worked together for decades, maintaining their dominance in the world chemical market. The Du Pont Corporation's monopoly patent on CFCs was about to expire and become public domain. It was therefore in Du Pont's interest to sponsor the Rio de Janeiro Earth Summit conference, and surprise, surprise; Du Pont secured the patent on the replacement HFC 134a gas. The Montreal Protocol to limit CFCs was revised and on 11th February, 1992, President Bush announced a ban on CFCs by 1995.