It is over 20 years since the introduction of HFC MDIs, and CFCs, first used for MDIs in 1956, are no longer used globally. Recently fluorocarbon propellants with a GWP less than 150 are being evaluated for safety and technical performance, but no decisions have yet been taken on their suitability and possible commercial use. The global impact of replacement of CFCs by HFCs and potential a further transition to <150 GWP fluorocarbon propellant is shown in the chart. Currently, HFCs used in MDIs account for about 3% of total global HFC emissions and about 0.03% of annual global greenhouse gas emissions. If a propellant with GWP <150 could be adopted then this could fall by at least a factor of about 10, with the propellant contributing up to about 0.003% of annual global greenhouse emissions.
TEAP May 2017 Progress Report page 26
TEAP MTOC 2014 Assessment Report page 36