The following explanations are based on the North American market
The traditional material for faucets
The traditional material for faucets is brass.
Brass is prized for faucets because of the advantages as below, It resists corrosion. It will not rust through like iron or steel. It has a relatively low melting point - making it easy to cast. It is soft enough to machine with little effort yet hardy enough to endure the rigors of life as a faucet. It takes finishes such as chrome plating very well, and is easily recycled. About 80% of the brass used in new faucets was previously used to make something else. Common yellow or "alpha" brass is about 60% copper and 30% zinc the rest being small amounts of other metals to give the brass specific properties. A little antimony or tin might be added to retard a form of corrosion known as dezincification which can weaken brass over time. A pinch of iron or manganese makes brass harder and nickel refines the grain structure improving strength. Aluminum may be added to make the brass stronger and more corrosion resistant. Admiralty and naval brasses used in salt-rich maritime environments contain a relatively high proportion of aluminum. The copper in brass is anti-microbial - it kills germs, a fact that has been known since the rise of the Pharaohs, but how it does so has only recently been uncovered. Note 1 Many fungi (mold and mildew) and most bacteria cannot survive in the presence of copper. In tests on colonies of E. Coli bacteria conducted by the EPA, 99.9% of the colony was killed after two hours of exposure to brass. Lead is added to make brass more malleable, less brittle, and easier to form. In faucet brass, however, lead is dangerous to human health, and especially dangerous to children because it can leach into the drinking water that passes through the faucet. According to the Environmental Protection Agency (RPA) lead can cause slowed growth, learning problems, hearing loss, anemia, hyperactivity, and behavior issues. Before 2014, a faucet could contain as much as 8% lead and still call itself lead-free. Now the maximum lead content in a faucet is 0.25% (1/4 of 1%), basically just a bare trace of lead. To ensure the absence of lead in the brass inside a faucet that is in contact with the water passing through the faucet, the faucet must be tested in a laboratory and certified lead-free. If it is not certified, it cannot be legally installed in a drinking water system.
