ODS emissions threaten ozone layer recovery
22nd April 2026
SWITZERLAND/UK: An increase in feedstock emissions of ozone depleting gases are said to be threatening the recovery of the ozone layer.
While the Montreal Protocol banned the use of ozone depleting substances (ODS), gases like the refrigerant HCFC22 were still allowed to be used as feedstock in the manufacture of other chemicals, including the lower GWP HFC and HFO replacement refrigerants.
This original ODS ban was based on the assumption that emission rates of feedstocks were only 0.5% of the amount produced and that feedstock production would decline in the future, with remaining emissions too small to significantly affect the stratospheric ozone or its recovery.
However, a new study by a multinational team of researchers claims that feedstock emissions are now typically 3.6% of production, and feedstock production and use has been rising rather than falling.
According to the study, rather than declining after 2003, the use of feedstock chemicals increased by 163% between 2000 and 2024. The highest growth between 2014 and 2024 was for HCFC22, CFC113 and 113a, HCFC142b and carbon tetrachloride.
The study is published in Nature Communications.
