Recyclability is one property which helps to establish the "green credentials" of a material, that is how "environmentally friendly" it is.

Brass consists of alloys predominantly copper with small amounts of zinc, lead, aluminium and manganese to provide improved properties. 

The brass industry throughout the world depends on the recycling of brass scrap. Making brass from copper and zinc would be uneconomical and wasteful of raw materials so, since new brass products are made from recycled scrap, brass is said to be sustainable.

In the UK brass manufacturers use almost 100% brass scrap.

Interesting Fact.
Copper is naturally present in the earths crust and is the oldest metal used by man. The first copper coins date back to 8700 BC.