R22 gets the cold shoulder

摘要

Back in the 1990s when MARPOL Annex VI was conceived, it was not so much nitrogen oxides, sulphur oxides or greenhouse gases that were the main subject of discussion but ozone-depleting substances such as chlorofluoro-carbons (CFCs) and hydrochlo-rofluorocarbons (HCFCs). Production and use of these substances were subject to the Montreal Protocol on Substances That Deplete the Ozone Layer, an international agreement of 1987 that took effect on 1 January 1989.