The Montreal Protocol on Substances that Deplete the Ozone Layer

The Montreal Protocol on Substances that Deplete the Ozone Layer is a global agreement to protect the Earth’s ozone layer by phasing out the chemicals that deplete it. This phase-out plan includes both the production and consumption of ozone-depleting substances. The landmark agreement was signed in 1987 and entered into force in 1989.

The parties to the Protocol meet once a year to make decisions aimed at ensuring the successful implementation of the agreement. These include adjusting or amending the Protocol, which has been done six times since its creation. The most recent amendment, the Kigali Amendment, called for the phase-down of hydrofluorocarbons (HFCs) in 2016. These HFCs were used as replacements for a batch of ozone-depleting substances eliminated by the original Montreal Protocol. Although they do not deplete the ozone layer, they are known to be powerful greenhouse gases and, thus, contributors to climate change.

The Montreal Protocol provided a set of practical, actionable tasks that were universally agreed on. The Protocol has successfully met its objectives thus far and continues to safeguard the ozone layer today. Thanks to the collaborative effort of nations around the world, the ozone layer is well on its way to recovery.

Decision XVII/7: List of uses of controlled substances as process agents

The Seventeenth Meeting of the Parties decided in Dec. XVII/7 to adopt the following uses of controlled substances as a revised table A for decision X/14:

Table A: List of uses of controlled substances as process agents

No. Process agent application Substance
1. Elimination of NCl3 in the production of chlorine and caustic CTC
2. Recovery of chlorine in tail gas from production of chlorine CTC
3. Manufacture of chlorinated rubber CTC
4. Manufacture of endosulphan (insecticide) CTC
5. Manufacture of isobutyl acetophenone (ibuprofen - analgesic) CTC
6. Manufacture of 1-1, bis (4-chlorophenyl) 2,2,2- trichloroethanol (dicofol insecticide) CTC
7. Manufacture of chlorosulphonated polyolefin (CSM) CTC
8. Manufacture of poly-phenylene-terephtal-amide CTC
9. Manufacture of fluoropolymer resins CFC-113
10. Manufacture of fine synthetic polyolefin fibre sheet CFC-11
11. Manufacture of styrene butadiene rubber CTC
12. Manufacture of chlorinated paraffin CTC
13. Photochemical synthesis of perfluoropolyetherpolyperoxide precursors of Z-perfluoropolyethers and difunctional derivatives CFC-12
14. Reduction of perfluoropolyetherpolyperoxide intermediate for production of perfluoropolyether diesters CFC-113
15. Preparation of perfluoropolyether diols with high functionality CFC-113
16. Bromohexine hydrochloride CTC
17. Diclofenac sodium CTC
18. Phenyl glycine CTC
19. Production of Cyclodime CTC
20. Production of chlorinated polypropene CTC
21. Production of chlorinated EVA CTC
22. Production of methyl isocyanate derivatives CTC
23. Production of 3-phenoxy benzaldehyde CTC
24. Production of 2-chloro-5-methylpyridine CTC
25. Production of Imidacloprid CTC
26. Production of Buprofenzin CTC
27. Production of Oxadiazon CTC
28. Production of chloradized N-methylaniline CTC
29. Production of Mefenacet CTC
30. Production of 1,3- dichlorobenzothiazole CTC
31. Bromination of a styrenic polymer BCM (bromochloromethane)
32. Synthesis of ascorbic acid CTC
33. Synthesis of ciprofloxacin CTC
34. Synthesis of norfloxacin CTC
35. Synthesis of 2,4-dichlorophenoxyacetic acid CTC
36. Synthesis of diperoxydicarbonate CTC
37. Production of sodium dichloroisocyanurate CTC
38. Production of radio-labelled cyanocobalamin CTC
39. Production of high modulus polyethylene fibre CFC-113