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.
Blue or Green Stains: Copper. Copper is seldom naturally present in a water supply, and usually results from the corrosion of copper plumbing. Signs of copper contamination in a water supply include: 1  Blue or green stains on showers, sinks, and other plumbing fixtures.s little as 0.3 ppm (parts per million), is enough iron to cause staining. Over time, this iron will react with water and air in a process known as oxidation and form rust, turning relatively new plumbing fixtures into eyesores and shortening their useful lifespans.