Ozone is a safeguard for the earth. Ozone protects the earth from a dangerous ultraviolet radiation. The ozone layer has been depleted because of chemicals used by human beings. When the concentration of the ozone layer decreases, the amount of UV light reaching the earth increases. As a result, when the amount of UV light reaching the earth increases the incidence of skin cancer and eye cataracts will increase. Chlorofluorocarbon (CFC) is one of the chemical used by humans that cause ozone depletion. CFCs are man-made chemicals which are used as refrigerants, solvents, foam blowing agents, and outside the United States, as aerosol propellants. Since CFCs are volatile and water insoluble, they can easily escape to the upper atmosphere. Then, they can react with ozone and deplete the ozone layer. Therefore, in order to save the ozone layer from being depleted, we should use other alternative chemicals such as butane and propane.