UPSC Prelims 2021 Q74: Environment & Ecology – Pollution & Waste Management
- (a) Low - density polyethylene
- (b) Polycarbonate
- (c) Polyethylene terephthalate
- (d) Polyvinyl chloride
Answer: (b) Polycarbonate
Explanation
Bisphenol A (BPA): Which Plastic?
| Plastic Type | Contains BPA? | Common Uses |
|---|---|---|
| Low-density polyethylene (LDPE) | NO | Grocery bags, packaging films |
| Polycarbonate (PC) | YES - KEY COMPONENT | Water bottles, baby bottles, sports gear, DVDs, eyewear |
| Polyethylene terephthalate (PET) | NO | Beverage bottles, food containers |
| Polyvinyl chloride (PVC) | NO (uses phthalates as plasticisers instead) | Pipes, cables, medical tubing |
Bisphenol A (BPA) is a monomer used in the manufacture of POLYCARBONATE plastics (and epoxy resins for can linings). BPA can leach from polycarbonate into food/drink, especially when heated. It is an endocrine disruptor mimicking estrogen. Many countries banned BPA in baby bottles.
Answer: (b) Polycarbonate.
Why each option is right or wrong
- (a) Incorrect. Low-density polyethylene (LDPE) is made from ethylene monomer, not BPA.
- (b) CORRECT. Bisphenol A (BPA) is a key structural component in the manufacture of POLYCARBONATE plastics (water bottles, baby bottles, sports gear). BPA is an endocrine disruptor and has been banned in baby bottles in many countries.
- (c) Incorrect. PET (Polyethylene Terephthalate) is made from terephthalic acid and ethylene glycol - no BPA.
- (d) Incorrect. PVC uses vinyl chloride monomer; phthalates (a different chemical group) are added as plasticisers, not BPA.
Key point
BPA (Bisphenol A) = key monomer in POLYCARBONATE plastics + epoxy resins. Endocrine disruptor - mimics estrogen. Banned in baby bottles in many countries. Found in water bottles, baby bottles, sports gear, DVDs, can linings.
Remember
Bisphenol A (BPA) is a key structural component in the manufacture of POLYCARBONATE plastics - used in water bottles, baby bottles, sports gear and can linings (epoxy resins). BPA is an endocrine disruptor and banned in baby bottles in many countries. Correct answer: (b).
Common mistakes
- Confusing BPA (polycarbonate) with phthalates (PVC plasticisers) - both are endocrine disruptors but different chemicals.
- Not knowing India's FSSAI regulations - BPA still permitted for most food-contact plastics with limits.
- Missing that 'BPA-free' plastics may contain BPS/BPF substitutes - similarly problematic.
Exam tip
Plastic-monomer pairs: PE (ethylene), PP (propylene), PVC (vinyl chloride + phthalates), PET (terephthalic acid + ethylene glycol), PS (styrene), PC (Bisphenol A). BPA = polycarbonate. Recyclable codes: 1=PET, 2=HDPE, 3=PVC, 4=LDPE, 5=PP, 6=PS, 7=Other (PC).
Sources
- US FDA - Bisphenol A (BPA) Regulatory Guidance
- FSSAI - Food Safety and Standards (Packaging) Regulations, 2018