UPSC Prelims 2023 Q20: Environment & Ecology – Climate Change & Greenhouse Gases
- (a) Only one
- (b) Only two
- (c) Only three
- (d) All four
Answer: (c) Only three
Explanation
Hydrofluorocarbons (HFCs) — Applications
HFCs were introduced as replacements for CFCs (ozone-depleting) under the Montreal Protocol. They do not damage the ozone layer but are potent greenhouse gases.
| Application | HFCs Used? | Details |
|---|---|---|
| 1. Aerosols | YES | HFCs used as propellants in aerosol sprays (deodorants, hairspray) — replaced CFC propellants |
| 2. Foam agents | YES | HFCs used as blowing agents in foam insulation, packaging foam |
| 3. Fire retardants | YES | HFCs (specifically HFC-227ea, Halon replacements) used in fire suppression systems in data centres and aircraft |
| 4. Lubricants | NO | Lubricants use petroleum-based, synthetic, or vegetable oils — not HFCs. HFCs have no lubricating properties. |
HFCs used in aerosols, foam agents, fire retardants → Only three.
Answer: (c) Only three.
Why each option is right or wrong
- (a) Incorrect. 'Only one' — HFCs are used across multiple industrial applications as CFC replacements.
- (b) Incorrect. 'Only two' — HFCs are used in fire suppression systems as well (replacing Halons which deplete ozone).
- (c) CORRECT. HFCs are used in aerosols, foam agents, and fire retardants. Lubricants do not use HFCs.
- (d) Incorrect. 'All four' — lubricants use petroleum-derived or synthetic oils, not halogenated fluorocarbons.
Key point
HFCs used in: Aerosols (propellants) + Foam (blowing agents) + Fire retardants (suppression systems) = 3 uses. Lubricants do NOT use HFCs. HFCs replaced CFCs but are themselves potent GHGs now being phased down under Kigali Amendment.
Remember
HFCs are used in aerosols, foam agents, and fire retardants — but NOT in lubricants. HFCs replaced ozone-depleting CFCs but are potent greenhouse gases being phased down under the Kigali Amendment (2016).
Common mistakes
- Including lubricants — lubricants require viscous, slippery substances; HFCs are gases/refrigerants with no lubricating properties.
- Not knowing HFCs replaced Halons in fire suppression — this is a less commonly known HFC application.
- Confusing HFCs with CFCs — HFCs don't deplete ozone (no chlorine) but ARE greenhouse gases, regulated under Kigali Amendment (2016).
Exam tip
HFCs = refrigerants, aerosol propellants, foam blowing agents, fire suppression (3+1=4 major uses minus lubricants). Kigali Amendment 2016 phasing down HFCs. UPSC tests HFC applications in context of climate/ozone law.
Sources
- UNEP — Montreal Protocol and Kigali Amendment
- Ministry of Environment, Forest and Climate Change — HFC Regulations in India