According to the Environmental Protection Agency, ozone depletion is mostly due to the corrosive actions of certain chemical compounds, such as refrigerants. Halting ozone depletion hinges on banning the use of these substances or preventing their release into the atmosphere. Because many of these compounds are extremely long-lived, molecules that escape into the atmosphere can cause ozone damage for decades.
Ozone molecules consist of three oxygen molecules, and are an important protective part of Earth's atmosphere. Certain catalysts, such as hydroxyls, nitric oxide, chlorine and bromine atoms, have the ability to break the bonds of ozone molecules, effectively destroying them by converting the oxygen into other compounds. Compounds called chlorofluorocarbons, or CFCs, contain many of these catalysts, and are particularly dangerous to the ozone layer. The Montreal Protocol banned their use in 1989, although they are not the only source of potentially ozone-destroying compounds.
As of 2014, any chemical that contains catalysts that could be dangerous to ozone is heavily regulated. Many of these substances are vital for manufacturing and chemical engineering, and are used in tightly-controlled conditions to prevent their escape into the atmosphere. The reduction in ozone-depleting chemicals is expected to allow the ozone layer to recover to pre-1980 levels by the year 2075.