The mechanism of action by which chlorofluorocarbons CFCs destroy the ozone layer involves a series of chemical reactions that occur in the stratosphere. The process can be summarized in the following steps:1. CFCs are released into the atmosphere from various sources, such as refrigeration systems, air conditioners, aerosol sprays, and foam production. Due to their stability and low reactivity, CFCs can persist in the atmosphere for several decades.2. When CFCs reach the stratosphere, they are exposed to ultraviolet UV radiation from the sun. This UV radiation causes the CFC molecules to break apart, releasing highly reactive chlorine atoms.3. The chlorine atoms then react with ozone O3 molecules, forming chlorine monoxide ClO and molecular oxygen O2 . This reaction can be represented as:Cl + O3 ClO + O24. The chlorine monoxide ClO molecules can react with another ozone molecule, releasing a chlorine atom and forming two oxygen molecules. This reaction can be represented as:ClO + O3 Cl + 2O25. The released chlorine atom can then react with another ozone molecule, repeating the process and leading to a catalytic destruction of ozone. A single chlorine atom can destroy thousands of ozone molecules before it is eventually removed from the stratosphere.To prevent the harmful impacts of CFCs on the environment, several measures have been taken:1. The Montreal Protocol: This international treaty, signed in 1987, aimed to phase out the production and consumption of CFCs and other ozone-depleting substances ODS . The protocol has been successful in reducing the global production and use of CFCs, leading to a decrease in their atmospheric concentrations.2. Development of alternatives: Safer alternatives to CFCs, such as hydrofluorocarbons HFCs and hydrochlorofluorocarbons HCFCs , have been developed for use in refrigeration, air conditioning, and other applications. These alternatives have a lower ozone-depletion potential compared to CFCs.3. Public awareness and education: Governments, non-governmental organizations, and educational institutions have been working to raise public awareness about the harmful effects of CFCs and the importance of protecting the ozone layer.4. Regulations and policies: National and regional regulations have been implemented to control the production, import, and use of CFCs and other ODS. These regulations help ensure compliance with the Montreal Protocol and promote the adoption of safer alternatives.By continuing to implement these measures and promote the use of environmentally friendly alternatives, we can further reduce the harmful impacts of CFCs on the ozone layer and the environment.