Vapor-compression refrigeration replaced, such as sulfur dioxide. Haloalkanes are also an order(s) of magnitude more expensive than petroleum derived flammable alkanes of similar or better cooling performance. Unfortunately, chlorine- and fluorine-bearing refrigerants reach the upper atmosphere when they escape. In the stratosphere, CFCs break up due to UV radiation, releasing their chlorine free radicals. These chlorine free radicals act as catalysts in the breakdown of ozone through chain reactions. One CFC molecule can cause thousands of ozone molecules to break down. This causes severe damage to the ozone layer that shields the Earth's surface from the Sun's strong UV radiation, and has
UV filter to sun irradiation, while swimming-pool water is required to be disinfected by chlorination, bromination, ozonation, or UV-irradiation. UV filters can undergo degradation and transformation to more toxic products. For example, Avobenzone undergoes transformation in the presence of chlorinated disinfection products and UV radiation to substituted chlorinated phenols and acetophenones, which are known for their toxicity. Some organic UV filters under UV radiation can generate reactive Oxygen Species (ROS) (OH, HO) (e.g. BP-3, octocrylene (OCR), OMC, phenylbenzimidazole sulphonic acid (PBS), PABA, etc.).The levels of HO in waters of Mediterranean beach reached 270 nM/day as a result of Sunscreens. HO as an