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.
This crust, called rust, is caused by the mixture of the metal with oxygen from water in the air. When moisture from the air, or from anywhere else, reaches an object with iron in it, oxygen in the water combines with atoms of iron to form molecules of a compound called iron oxide.ther metals besides iron and steel can rust when exposed to moisture, but not all rust is ârust-colored.â For instance, when copper or bronze rusts, it turns green. The green crust is called a patina.