Question 35 from UPSC CSE 2021 - S&T

Question

Bisphenol A (BPA), a cause of concern, is a structural/key component in the manufacture of which of the following kinds of plastics?

Accepted Answer

Correct Option: B. Polycarbonate

Strategy: Focus on matching the chemical name 'Bisphenol A' with specific plastics. Polycarbonate is the crucial match here, as BPA is the main building block used in its synthesis. The other listed plastics (LDPE, PET, PVC) are made from entirely different monomers and do not require BPA in their manufacture.

Key Info: Bisphenol A (BPA) is an organic synthetic compound widely used in the production of polycarbonate plastics and epoxy resins.

- Polycarbonate: BPA is polymerized with phosgene to form polycarbonate, a strong, transparent plastic often used in reusable water bottles, food storage containers, eyewear lenses, and certain medical devices. BPA's presence makes polycarbonate hard and shatter-resistant.
- Low-density polyethylene (LDPE): Made from polymerizing ethylene gas at low pressure, without any need for BPA.
- Polyethylene terephthalate (PET): Made from the polycondensation of terephthalic acid and ethylene glycol, has no relation to BPA.
- Polyvinyl chloride (PVC): Produced by polymerizing vinyl chloride monomer, again not involving BPA.

### Health and Environmental Context

- BPA has been found to leach into foods and beverages stored in containers made from polycarbonate plastics, especially at high temperatures.
- It is recognized as an endocrine disruptor, mimicking estrogen and potentially causing adverse health effects.
- Due to health concerns, BPA is increasingly being regulated in food-contact materials, especially for baby bottles and sippy cups.

### Regulation and Alternatives

- Many countries, including the European Union, the United States, and India, have restricted the use of BPA in baby products and food containers.
- BPA-free plastics often use alternatives such as bisphenol S (BPS), but their safety profiles are still under investigation.

Answer

Option A: Low-density polyethylene

Answer

Option C: Polyethylene terephthalate

Answer

Option D: Polyvinyl chloride