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 agent in aerosol cans which of the statement given above is/are correct?

The correct answer is C (1, 3 and 4 only). CFCs were used as blowing agents in making rigid and flexible plastic foams, as solvents for cleaning and degreasing precision electronic components, and as propellants in aerosol cans. Each of these uses was common before the phase-out.

• Statement 1 is correct: CFCs acted as blowing agents that gave polyurethane and other plastic foams their cellular structure.
• Statement 2 is wrong: CFCs were not a standard input in making tubeless tyres. Tyre makers use rubber, carbon black and other compounds, so this statement is a distractor.
• Statement 3 is correct: CFC-113 was a widely used solvent for cleaning circuit boards and electronic components.
• Statement 4 is correct: CFCs served as propellants in aerosol cans.

The core concept is ozone-depleting substances and their regulation under the Vienna Convention (1985) and the Montreal Protocol (1987). India's phase-out is now largely complete under the Montreal Protocol framework, so the uses in the question are historical. For Mains, this links to international environmental governance and the trade-off between industrial convenience and global commons.

Trap: Aspirants often accept statement 2 because it sounds technical. Check each use against what the product actually requires, rather than assuming every listed use is valid.