The use of materials with recycled content reduces the environmental impact of extracting and processing non-renewable and virgin materials. Materials, products, components, fixtures and fittings made with recycled content can contain post- or pre-consumer content.  Post-consumer content is waste that is recycled after the product has been used by a consumer. It may include construction or demolition debris such as recycled aggregate, steel and aluminum building elements, materials sorted for recycling purposes such as aluminum cans and glass bottles, and landscaping waste such as branches and leaves. Pre-consumer waste is raw material that has never been used by a consumer such as wood chips and sawdust. Pre-consumer materials are often by-products of manufacturing processes that can be recycled and reused.