Life-cycle assessments

A life-cycle assessment or LCA is a 'cradle to grave' analysis of the impact of a manufactured product on the environment. The main stages are:

  1. obtaining the raw materials needed
  2. manufacturing the product
  3. using the product
  4. disposing of the product at the end of its useful life
Circular line linking disposal, raw material, manufacture and use in a continuous loop.The four main stages of the life-cycle assessment

The four main stages

At all stages, an LCA is likely to include information about the use of energy, transport of materials, and the release of waste substances into the environment.

1. Raw materials

All the raw materials we need come from the Earth's crust, atmosphere or oceans, or are due to living organisms. Obtaining these materials has an impact on the environment, including:

2. Manufacture

The manufacture of products has an impact on the environment, including:

  • using up land for factories
  • the use of machines and people

3. Use

The impact of a product on the environment during its use depends on the type of product. For example, a wooden chair has very little impact, unless it needs cleaning or repair. On the other hand, a car will have a significant impact.

4. Disposal

The disposal of old products has an impact on the environment, including:


The table shows some data about the energy needed in the life cycle of a pillow case.

Life cycle stageEnergy use
Raw materials10%

Discuss the use of energy during the life cycle of the pillowcase, and describe one way in which the energy use could be significantly reduced.

15% of the energy use is associated with making the pillowcase, and very little in disposing of it. The greatest use of energy happens when it is being used, probably because of washing, drying and ironing the pillowcase. Energy use could be reduced by drying it outside and without ironing it.