📌 The Question:

Consider the following:

1. Aerosols
2. Foam agents
3. Fire retardants
4. Lubricants

In the making of how many of the above are hydrofluorocarbons used?

(a) Only one
(b) Only two
(c) Only three
(d) All four

✅ Correct Answer: (d) All four

🧑‍🏫 Classroom Explanation

Hydrofluorocarbons (HFCs) are fully synthetic industrial chemicals, developed mainly as substitutes for ozone-depleting substances like CFCs and HCFCs.

They are widely used in:

• Aerosols – as propellants
• Foam agents – especially insulating foams
• Fire retardants / fire protection systems
• Lubricants – particularly synthetic lubricants used in HFC-based refrigeration and air-conditioning equipment

Thus, all four listed applications involve the use of HFCs.

⚡ Curiosity Raiser

A chemical that saved the ozone layer… but now threatens the climate 🌍🔥

📚 Enrich Notes (UPSC Edge)

• HFCs:
  • Do not deplete ozone
  • But have very high Global Warming Potential (GWP)
• Though only ~1% of total GHG emissions, their warming impact can be hundreds to thousands of times stronger than CO₂
• Kigali Amendment (2016) to the Montreal Protocol:
  • Mandates >80% phase-down of HFCs by 2050
  • Entered into force in 2019

🕊️ IAS Monk Whisper

“Every solution creates a new responsibility — climate remembers everything.”