The Montreal Protocol on Substances that Deplete the Ozone Layer (1987) is an international treaty that aims to protect the ozone layer by phasing out the production and use of approximately 100 synthetic chemicals. Specifically, it calls for phasing out certain Ozone Depleting Substances (ODS), including CFCs, halons, methyl bromide, HCFCs, and most recently, HFCs. Universal ratification of the Montreal Protocol and growing ratification of the Kigali Amendment mean that there are existing commitments on ODS and HFC use at the country level. By integrating the Montreal Protocol and its amendments into purchasing decisions for equipment and building materials, USAID will ensure that its projects comply with current and future requirements on ODS and HFC use at the local, regional, and international level.