Life cycle assessment and recycling — Eduqas GCSE Combined Science

Life cycle assessment (LCA) is a systematic method used to evaluate the environmental impact of a product throughout its entire life — from raw material extraction, through manufacturing and use, to disposal or recycling. In WJEC GCSE Combined Science, you'll learn how to analyse each stage of a product's life cycle, considering factors such as energy use, resource depletion, pollution, and waste generation. This topic is crucial because it helps us make informed choices about materials and processes, balancing economic needs with environmental sustainability.

Recycling is a key strategy within LCA to reduce environmental impact. By recovering materials from waste and reprocessing them into new products, we conserve natural resources, save energy, and reduce landfill. You'll study the recycling of common materials like metals, glass, paper, and plastics, and understand the challenges such as contamination and energy costs. This topic connects to broader themes in chemistry and sustainability, showing how scientific principles can be applied to real-world environmental issues.

Mastering LCA and recycling is essential for the WJEC exam, as questions often ask you to compare products or justify choices using LCA data. You'll need to interpret simple LCA diagrams, identify the most environmentally damaging stages, and suggest improvements. This knowledge also supports your understanding of the 'Reduce, Reuse, Recycle' hierarchy and the role of science in achieving a circular economy.

• →The four main stages of a life cycle assessment: raw material extraction, manufacturing and packaging, use and maintenance, and disposal or recycling.
• →Environmental impacts considered in each stage: energy consumption, water usage, release of pollutants (e.g., CO2, SO2), and waste generation.
• →The difference between open-loop recycling (e.g., plastic bottles turned into fleece) and closed-loop recycling (e.g., aluminium cans recycled into new cans).
• →How recycling reduces the need for extracting virgin materials, saving energy and reducing pollution — e.g., recycling aluminium saves 95% of the energy needed to produce it from bauxite ore.
• →The limitations of LCA: it can be subjective (e.g., choosing which impacts to include) and data may be incomplete or vary by location.

• Identification of the stages of a life cycle assessment (raw material extraction, manufacture, use, disposal)
• Comparison of environmental impacts between different materials or products
• Explanation of why recycling is viable for specific materials
• Evaluation of factors influencing recycling decisions (e.g., energy use, economic cost, environmental benefit)

• 💡When interpreting LCA data, look for specific environmental costs like energy consumption or carbon footprint
• 💡Be prepared to justify why a specific material is chosen for a product based on its life cycle data
• 💡Use clear, logical steps when evaluating the viability of a recycling process
• 💡When comparing two products using LCA, always refer to specific stages. For example, 'The disposable cup has a higher impact in the raw material stage because it uses virgin paper, whereas the reusable cup has a higher impact in the use stage due to washing.' This shows detailed understanding.
• 💡Use correct terminology: 'life cycle assessment' (not 'life cycle analysis'), 'raw material extraction', 'manufacturing', 'disposal'. Avoid vague terms like 'bad for the environment' — be specific about the impact (e.g., 'releases more carbon dioxide').
• 💡Remember that recycling is not always the best option. The waste hierarchy is: reduce, reuse, recycle. In exam answers, consider whether a product could be redesigned to use less material or be reused before discussing recycling.

• Failing to consider all stages of a product's life cycle in an assessment
• Confusing the environmental impact of manufacture with the impact of disposal
• Assuming all recycling processes are equally energy-efficient or economically viable
• Misconception: 'Recycling always has zero environmental impact.' Correction: Recycling still uses energy for collection, sorting, and reprocessing, and can produce pollution. However, it usually has a lower impact than extracting and processing virgin materials.
• Misconception: 'Biodegradable materials are always better for the environment.' Correction: Biodegradable plastics may only break down under specific conditions (e.g., industrial composting) and can release methane if landfilled. Their LCA must consider the entire life cycle, not just disposal.
• Misconception: 'LCA gives a definitive answer on which product is best.' Correction: LCA results depend on the boundaries set and the assumptions made. Different LCAs on the same product can give different results, so they should be used as a guide, not an absolute truth.