UPSC Prelims 2012 · Question 17 of 98

UPSC Prelims 2012 question on CFC Uses Ozone Depletion

Consider the following statements:

Chlorofluorocarbons, known as ozone-depleting substances, are used

1. In the production of plastic foams.

2. In the production of tubeless tyres.

3. In cleaning certain electronic components.

4. As pressurizing agents in aerosol cans.

Which of the statements given above is/are correct?

  1. 1, 2 and 3 only
  2. 4 only
  3. 1, 3 and 4 only
  4. 1, 2, 3 and 4
Show answer

Answer: C. 1, 3 and 4 only

Verdict

Correct Answer: 1, 3 and 4 only

Statements 1, 3 and 4 are correct because CFCs were used in plastic foams, electronic cleaning and aerosol propellants, while they are not used in tubeless tyre production.

Analysis

Chlorofluorocarbons are ozone-depleting substances that were earlier used widely in industries because they are stable, non-flammable and effective as refrigerants, solvents, blowing agents and propellants.

Statement by statement

1. In the production of plastic foams — Correct

CFCs were used as blowing agents in the production of plastic foams such as polyurethane and polystyrene.

They helped expand the polymer and create a light, cellular foam structure used in insulation, packaging and cushioning.

2. In the production of tubeless tyres — Incorrect

CFCs are not used in the production of tubeless tyres.

Tyre manufacturing mainly involves rubber processing and vulcanization, where materials like sulphur and carbon black are used. CFCs have no major functional role here.

3. In cleaning certain electronic components — Correct

CFCs, especially CFC-113, were used as industrial solvents for cleaning precision electronic components.

They were useful because they were non-flammable and evaporated without leaving much residue.

4. As pressurizing agents in aerosol cans — Correct

CFCs were earlier used as propellants in aerosol cans.

They could remain liquid under pressure and turn into gas when released, helping spray products like deodorants, hair sprays and insecticides.

Extra UPSC info

* CFCs are stable in the lower atmosphere but break down in the stratosphere under UV radiation.

* They release chlorine atoms that destroy ozone molecules.

* The Montreal Protocol, 1987 led to the global phase-out of CFCs.

* CFCs were also used as refrigerants in refrigerators and air conditioners.

* HCFCs and HFCs were introduced as substitutes, but HFCs are potent greenhouse gases.

* The Kigali Amendment deals with phasedown of HFCs.

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