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.
The reactions that produce molecular oxygen (O2) take place in. The light reactions alone. A flask containing photosynthetic green algae and a control flask containing water with no algae are both placed under a bank of lights, which are set to cycle between 12 hours of light and 12 hours of dark. The dissolved oxygen concentration in both flasks are monitored.