Bisphenol A (BPA), a cause of concern, is a structural/key component in the manufacture of which of the following kinds of plastics?
Contents13
- ALow-density polyethylene
- BPolycarbonate
- CPolyethylene terephthalate
- DPolyvinyl chloride
Show answer
Answer: (B) Polycarbonate
Bisphenol A (BPA) is an industrial chemical that is a key building block in making polycarbonate plastic — a hard, clear plastic used in water bottles, baby bottles, food containers, and tableware.
BPA is also in epoxy resin linings inside food cans.
It can leach from containers into food, especially when heated.
BPA exposure has been linked to potential health effects.
It is not a component of polyethylene (a), PET (c), or PVC (d).
Answer: (b).
BPA is the key chemical building block used specifically to manufacture polycarbonate plastic, which makes hard, clear containers like water bottles and baby bottles.
BPA can leach from plastic containers into food and drinks, especially when heated, creating potential health risks that have made it a major public health concern.
The question tests whether students can distinguish BPA-containing polycarbonate from other common plastics like polyethylene, PET, and PVC that do not contain BPA.
Bisphenol A (BPA)
Science And Technology Bisphenol A BPA
Bisphenol A (BPA): Chemical Structure, Uses & Health Concerns
BPA is a key building block in polycarbonate plastic manufacturing
Found in water bottles, baby bottles, and epoxy resin linings in food cans
Can leach into food, especially when heated
Linked to endocrine disruption and reproductive health issues
What is BPA
Bisphenol A (BPA) is an industrial chemical used since the 1960s to make certain plastics and resins. It acts as a monomer — a building block molecule that links together to form longer polymer chains in plastic manufacturing.
BPA Applications
Product Type | BPA Use | Common Examples | Exposure Risk |
|---|---|---|---|
Polycarbonate plastics | Key structural component | Water bottles, baby bottles, food containers | High when heated |
Epoxy resins | Protective coating | Food can linings, bottle caps | Medium through food contact |
Thermal paper | Developer chemical | Receipt paper, tickets | Low through skin contact |
Dental materials | Resin component | Some dental sealants | Low after curing |
Health Concerns
Endocrine disruptor — mimics estrogen hormone in the body
Linked to reproductive problems, developmental issues in children
Associated with increased risk of certain cancers and metabolic disorders
Heat increases leaching — hot liquids cause more BPA release from containers
Question Context
This question tests knowledge of plastic chemistry. The correct answer is polycarbonate because BPA is literally a structural monomer in its polymer chain. The other plastics (LDPE, PET, PVC) are made from completely different chemical building blocks.
Don't confuse with PET plastic — PET bottles may contain BPA but BPA is not a structural component of PET
LDPE (plastic bags) and PVC (pipes) have no BPA in their chemical structure
BPA is in epoxy resins too, but the question asks about plastics specifically
Polycarbonate Plastic
Science And Technology Polycarbonate
Polycarbonate Plastic: Properties, Manufacturing & Applications
Thermoplastic made from BPA and phosgene as key monomers
Hard, clear, shatter-resistant — stronger than glass
Used in water bottles, eyewear, electronics, automotive parts
Structure & Properties
Polycarbonate is a thermoplastic polymer formed by linking BPA molecules with carbonate groups. This creates a strong, transparent plastic that combines the clarity of glass with much higher impact resistance.
Key Properties
Optical clarity — nearly transparent like glass
High impact strength — 200x stronger than glass
Temperature resistant — stable from -40°C to 140°C
Lightweight — 50% lighter than glass
UV resistant when treated with coatings
Applications by Sector
Sector | Products | Why Polycarbonate | BPA Concern Level |
|---|---|---|---|
Food & Beverage | Water bottles, baby bottles, food containers | Clear, unbreakable, reusable | High |
Electronics | Phone cases, laptop bodies, LED housings | Impact resistance, heat stability | Low |
Automotive | Headlight lenses, dashboards, windows | Shatter-proof, UV resistant | None |
Construction | Roofing sheets, safety glazing | Weather resistant, light transmission | None |
All polycarbonate contains BPA in its backbone structure — it's chemically unavoidable
'BPA-free' alternatives use different plastics like Tritan, not true polycarbonate
Common Plastic Types
Science And Technology Low-density polyethylene Polyethylene terephthalate Polyvinyl chloride
Major Plastic Types: Structure, Properties & Applications
LDPE (#4) — soft, flexible, used in bags and films
PET (#1) — clear, strong, used in beverage bottles
PVC (#3) — rigid or flexible, used in pipes and packaging
None contain BPA as a structural component
Plastic Comparison
Plastic Type | Recycle Code | Key Monomers | Properties | Common Uses |
|---|---|---|---|---|
Low-Density Polyethylene (LDPE) | #4 | Ethylene | Soft, flexible, translucent | Plastic bags, food wraps, squeeze bottles |
Polyethylene Terephthalate (PET) | #1 | Ethylene glycol + terephthalic acid | Clear, lightweight, strong | Beverage bottles, food jars, textiles |
Polyvinyl Chloride (PVC) | #3 | Vinyl chloride | Rigid or flexible, chemical resistant | Pipes, medical tubing, packaging |
Polycarbonate (PC) | #7 | BPA + phosgene | Hard, clear, impact resistant | Water bottles, eyewear, electronics |
Chemical Structure Differences
Polyethylene plastics (LDPE, HDPE) — only carbon and hydrogen atoms, no BPA
PET — contains oxygen in ester linkages but built from different monomers than BPA
PVC — contains chlorine atoms, completely different chemistry from polycarbonate
Only polycarbonate has BPA as its fundamental building block
Plastic Identification
Source: Good Housekeeping — Swap Single-Use Items with Sustainable Alternatives · www.goodhousekeeping.com
Don't assume all clear plastic bottles contain BPA — most beverage bottles are PET (#1), not polycarbonate
PVC and polycarbonate both start with 'P' but have completely different chemistry
LDPE vs HDPE — both polyethylene but different density and flexibility