The Montreal Protocol controls the production and consumption of a range of chemicals that damage the ozone layer (i.e. ozone depleting substances, ODS). In the Kigali Amendment the Protocol was extended to control the production and consumption of HFCs. These are not ODS, but they are very powerful greenhouse gases (GHGs). This Fact Sheet provides details of which substances are controlled under the Montreal Protocol and gives examples of related substances that are not included in these controls.