This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Both metal and copper oxidize when exposed to oxygen and this is a natural process. Copper that is exposed to the outside environment is more likely to turn green and that is why copper vases and decorative pieces in gardens are often green.
Copper can be mixed with other metals to form alloys, such as bronze (copper and tin) and brass (copper and zinc). Oxidized copper, or copper that has been exposed to air, develops a green coating or âpatinaâ that can be seen on old copper pennies, the Statue of Liberty, and copper roofs.