Regulation of Ozone-Depleting Substances (ODS)
When we talk about protecting the ozone layer, two names always come up:
Vienna Convention and Montreal Protocol.
Think of them as the Constitution and law of global ozone protection.
Vienna Convention (1985)
Imagine the world realizing in the 1980s that the ozone layer—our natural sunscreen 😊—was thinning.
But countries did not yet know exactly what actions to take.
So, in 1985, the world adopted the Vienna Convention for the Protection of the Ozone Layer.
Key Points
- It created a global monitoring and reporting mechanism.
- It did not impose bans but created the framework to take future binding actions.
- It prepared the ground for the Montreal Protocol.
Montreal Protocol (1987)
If Vienna Convention is the framework, Montreal Protocol is the actual implementation strategy.
Why is this protocol legendary?
- It is considered the most successful environmental treaty ever.
- All 197 countries are parties—universal ratification.
- It mandated the phase-out of ODS such as CFCs, Halons, Carbon Tetrachloride, HCFCs etc.
- Every ODS has a deadline for complete elimination.
Result of global cooperation
- The ozone hole over Antarctica is healing.
- Scientific models show the ozone layer will return to 1980 levels by 2050–2070.
- NOAA studies confirm declining atmospheric ODS concentrations.
This success story shows that humanity can solve global environmental crises if it acts together.
Quito Adjustment (2018): Strengthening the Protocol
In 2018, at Quito (Ecuador), parties adopted an adjustment aimed to:
- Avoid 1°C of future warming.
This shows how the Protocol now addresses climate change, not just ozone depletion.
Compliance Issues: The Case of CFC-11
Even with strict treaties, violations happen.
What’s happening with CFC-11?
- CFC-11 is banned under the 1987 Montreal Protocol.
- Yet it still contributes 25% of all chlorine reaching the stratosphere.
- 40–60% of global CFC-11 emissions have been traced to China.
- Reason? Some foam industries illegally use CFC-11 because it is cheaper than alternatives like HCFC-141b.
China committed to eliminating CFC-11 in 2010, but enforcement issues persist.
Kigali Amendment (2016)
(Addressing Greenhouse Gases)
Even after phasing out ODS, the world needed replacements.
But the replacements—HFCs (Hydrofluorocarbons)—became a new problem.
Why?
- HFCs do not deplete ozone,
- but they have very high Global Warming Potential (GWP).
So in 2016, 197 countries adopted the Kigali Amendment.
Its goal
- Reduce HFC production and use by 80–85% by 2045.
Impact
- Can reduce global warming by up to 0.5°C by 2100.
- Important for reducing Urban Heat Island intensity (since ACs use HFCs).
India’s Position Under the Kigali Amendment
India has a lenient schedule because it uses only 3% of global HFCs.
India’s reduction timeline
- 10% reduction → 2032
- 20% reduction → 2037
- 30% reduction → 2042
- 85% reduction → 2047 (final phase-down)
This gives Indian industries time to adapt.
HFOs: The Next-Generation Refrigerants
Since HCFCs and HFCs have problems, a new family emerged: HFOs (Hydrofluoro Olefins).
Characteristics:
- Contain at least one double bond.
- Zero Ozone Depleting Potential (ODP).
- Very low GWP → climate-friendly.
Comparison Table (Simplified)
| Chemical Class | ODP | GWP |
|---|---|---|
| CFCs | High | High |
| HCFCs | Low | High |
| HFCs | Zero | High |
| HFOs | Zero | Very Low |
ODS Rules in India
India enforces ODS regulation through rules under the Environment (Protection) Act, 1986.
These rules:
- Set deadlines for eliminating ODS.
- Regulate production, trade, import, export.
- Allow exemptions only for essential medical uses.
Important deadlines:
- CFCs: prohibited after 1 Jan 2003 (except MDIs earlier)
- Halons: prohibited after 1 Jan 2001
- Carbon Tetrachloride, Methyl Chloroform: prohibited after 1 Jan 2010
- Methyl Bromide: allowed till 1 Jan 2015
- HCFCs (interim substitutes): allowed till 1 Jan 2040
India Phases Out HCFC-141b (2020)
HCFC-141b is used mainly in rigid polyurethane foams—important for insulation, cold chains, refrigeration, buildings.
India’s actions:
- Completely phased out HCFC-141b from 1 Jan 2020.
- Banned both its production and imports.
- Earlier, India had already phased out CFCs, Halons, Methyl Chloroform, etc.
This is a major contribution to fulfilling Montreal Protocol commitments.
Closure of Hindustan Fluorocarbons Limited (HFL)
HFL manufactured HCFC-22, a refrigerant and feedstock for PTFE (Teflon).
Why was it closed?
- HCFC-22 production quotas have been drastically reduced under the Montreal Protocol.
- The limited production allowed was not sufficient to run the plant economically.
Thus, the government approved the company’s closure.