Heat pump the brand name Freon, a trademark of DuPont. Its manufacture is now banned or severely restricted by the Montreal Protocol of August 1987 because of the damage that CFCs cause to the ozone layer if released into the atmosphere. One widely adopted replacement refrigerant is the hydrofluorocarbon (HFC) known as R-134a (1,1,1,2-tetrafluoroethane). Heat pumps using R-134a replaced R-12 (dichlorodifluoromethane) and have similar thermodynamic properties but with insignificant ozone depletion potential and a somewhat lower global warming potential. Other substances such as liquid R-717 ammonia are widely used in large-scale systems, or occasionally the less corrosive but more flammable propane or
Protocol (politics) Discrimination against Women is supplemented by an Optional Protocol. Protocol (politics) Protocol can mean any logbook or other artifact (forged or authentic) of a political meeting between persons from different nations. The most notorious example of a forged logbook is "The Protocols of the Elders of Zion". In international law, a treaty that supplements or adds to a pre-existing treaty is often given a name that includes "Protocol" in its title. For example, the Kyoto Protocol was supplemental to the United Nations Framework Convention on Climate Change; Protocol I, Protocol II, and Protocol III supplement the 1949 Geneva Conventions; and