10 2 life cycle analysis and recycling

Lifecycle assessments are carried out to assess the environmental impact of a product.

The four main stages of a life cycle assessment are:

True. It is fairly easy to quantify the use of water, resources, energy sources and production of some waste.

False. It is not easy to allocate a numerical value to the polluting effect of a product when carrying out a LCA.

True. A life cycle assessment is not an objective process.

Materials such as glass and metal need to be recycled and reused because they are made from natural but finite sources.

Advantages of recycling materials includes:

Two disadvantages of recycling metals include:

Recycling reduces the use of fossil fuels.

A glass bottle can be recycle by being crushed and melted, and then remoulded into a different shape.

Metals can be recycled by heating the metal until it melts and recasting them into a new shape.

True. It is much more energy efficient to recycle metals than it is to extract them as melting and re-moulding requires less energy.

Two factors that determine the amount of separation required for recycling are:

True. Most of the energy needed to produce raw materials, such as glass, comes from limited resources.

False. Glass is separated by colour and chemical composition before recycling.