Plastics: useful properties and disposal consequences
Connect polymer materials' useful durability with landfill and ocean accumulation, while recognising that burning can produce toxic gases.
Exam scope and assessment notes
Core and Extended · Chemistry 0971, 2026–2028. Deducing other repeat units, condensation structures and proteins follows in the Extended lessons. Cambridge states that IGCSE 0971 has the same subject content as IGCSE 0620, with 9–1 grading. This StudyForA pathway maps the 2026–2028 syllabus only. This 9–1 graded qualification is available only in a limited number of administrative zones. Confirm that your centre can enter you for this code and exam series with Cambridge International. Cambridge has published a separate syllabus for 2029. StudyForA has not reconciled that version yet; this page supports exams in 2026, 2027 and 2028 only.
Before you begin
- Define polymer and distinguish material properties from a use.
- Explain that a disposal method may change one problem while leaving another.
Work on paper. Try each question before revealing help, and explain why your method works.
Quick readiness check
What are plastics made from?
What you will learn
- State that plastics are made from polymers.
- Explain how properties affect disposal and describe the required landfill, ocean and toxic-burning challenges.
The useful property can persist after use
Plastics are made from polymers. Many common plastics are durable, resist chemical attack and do not readily biodegrade. Those properties can make a product useful while also allowing waste to persist after disposal. A lightweight, durable item does not disappear chemically just because it is no longer wanted.
Avoid saying every polymer is a non-biodegradable plastic: natural polymers such as proteins differ from the common plastic examples. Plastic materials also differ in their composition and properties. Use the supplied material information when deciding whether it can be reused, separated or processed; the name plastic alone does not establish every disposal behaviour.
Describe the three required environmental challenges
Persistent plastic waste can occupy landfill sites and accumulate over time. Plastic entering oceans can accumulate there rather than being removed merely by moving the waste out of sight. Fragmenting a piece into smaller pieces is not the same as completely breaking its polymer molecules down into harmless products.
Burning some plastics can produce toxic gases; the gases depend on composition and combustion conditions. Burning is therefore not a universal consequence-free solution to landfill accumulation. Managed waste treatment and recycling require suitable processes and material information; neither the word recyclable nor a single disposal choice guarantees that waste has actually been collected or successfully processed.
Pause and explain
Why can durability be both useful and a disposal problem?
Worked example
A hypothetical durable packaging polymer resists biodegradation. Explain a useful application property and two disposal concerns without claiming all polymers behave identically.
Show the worked solution
- Durability can protect packaging contents during use.
- The same persistence can contribute to accumulation in landfill and, if released, oceans.
- Burning certain plastics can produce toxic gases, so it is not automatically a consequence-free disposal route.
Answer Durability helps during use but can cause persistent landfill/ocean waste; burning certain plastics can also produce toxic gases.
Try a topic test
Choose Easy, Normal or Difficult. Save your answers and open worked review after finishing.
Test this topic →From guided practice to a new situation
Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.
State what plastics are made from and connect one useful property to a disposal implication.
Give me a hint
Follow the same property from use into the waste stage.
Compare my reasoning
- Plastics are made from polymers.
- Durability or resistance can help a product last during use.
- For a persistent common plastic, those properties can also slow breakdown and leave accumulated waste.
Plastics are made from polymers; useful durability can also make discarded material persist.
Look for these in your work
- Composition and property are both named.
- The disposal implication follows from the supplied property.
Describe the required landfill, ocean and burning challenges for plastics.
Give me a hint
Give a consequence for each route rather than only a location name.
Compare my reasoning
- Persistent plastic can accumulate and occupy landfill sites.
- Waste entering oceans can accumulate there instead of disappearing.
- Burning certain plastics can form toxic gases, depending on composition and conditions.
Persistent landfill waste; accumulation in oceans; possible toxic gases from burning certain plastics.
Look for these in your work
- All three required challenges appear.
- The burning claim is qualified by material and conditions.
A proposal breaks discarded packaging into tiny fragments, releases them into the ocean, then says landfill pressure and all pollution are solved. Assess the reasoning using the supplied persistent-plastic model.
Give me a hint
Check whether the polymer was chemically decomposed or merely moved and fragmented.
Compare my reasoning
- Making smaller pieces does not demonstrate chemical decomposition of the polymer chains.
- Releasing the pieces can replace landfill accumulation with ocean accumulation.
- The proposal therefore does not show all environmental challenges are solved; waste collection and appropriate processing still matter.
Fragmenting and relocating persistent plastic does not establish chemical breakdown; ocean accumulation can remain even if landfill receives less waste.
Look for these in your work
- Physical fragmentation and chemical decomposition are separated.
- A changed waste location is not treated as removal of every challenge.
Common mistakes
- Equating all polymers with identical non-biodegradable plastics.
- Treating smaller fragments as complete chemical decomposition.
- Assuming burning every plastic produces only harmless gases.
- Calling a recyclable label proof that collection and recycling already happened.
What can you explain now?
Which three plastic-waste challenges are specified?
Compare with the explanation
Landfill disposal, ocean accumulation and formation of toxic gases from burning.
Useful persistence and chemical resistance can complicate disposal after the product's use.
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Make it stick
Explain a plastic's property during use and after disposal, then recall all three required environmental challenges without making universal claims about every polymer.
If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.