The Montreal Protocol was designed to eliminate substances that deplete ozone by reaction with ozone (O3) in the stratosphere
- Chlorofluorocarbons (CFCs) and Halons
- Hydrochlorofluorocarbons (HCFCs) e.g. R22
- Hydrobromofluorocarbons (HBFCs)
- Carbon tetrachloride
- Methyl chloroform (1,1,1-trichloroethane)
- Methyl bromide
- Bromochloromethane
- Hydrofluorocarbons (HFCs)
The Montreal Protocol works by increasingly limiting supply rather than an outright ban. The use of listed substances as solvents or reagents should be avoided.
By 2020, most of the new HCFCs had been phased out by developed countries. Meanwhile, developing countries are still following their stepwise reduction through until a complete phase-out by 2030.
In 2016, hydrofluorocarbons (HFCs) were also added to the list of controlled substances as part of the Kigali Amendment. Whilst they don’t deplete ozone, uncontrolled growth of HCF emissions damages this century’s target to keep the global temperature rise at 2oC or below. Developed countries were therefore expected to begin a phase-down by 2019 and developing countries from 2024-2028 in a bid to have a total phase-down of HCFs by 2047.
