Air conditioning eventually reach the upper atmosphere. Once the refrigerant reaches the stratosphere, UV radiation from the Sun homolytically cleaves the chlorine-carbon bond, yielding a chlorine radical. These chlorine radicals catalyze the breakdown of ozone into diatomic oxygen, depleting the ozone layer that shields the Earth's surface from strong UV radiation. Each chlorine radical remains active as a catalyst until it binds with another radical, forming a stable molecule and quenching the chain reaction. Prior to 1994, most automotive air conditioning systems used R-12 as a refrigerant. It was replaced with R-134a refrigerant, which has no ozone depletion potential. Old R-12 systems
Lauriston S. Taylor Lauriston S. Taylor Lauriston S. Taylor (1 June 1902 – 26 November 2004) was an American physicist known for his work in the field of radiation protection and measurement. He established standards for X-ray radiation exposure for the first time in the 1920s, which eventually led to a group of government organizations that set the standards over the next 50 years. Taylor remained active in debates about radiation exposure into his 80s, often advocating the viewpoint that small doses of radiation were not important. He served as president of the Health Physics Society (HPS) from 1958 to 1959. He was