G-6, benzotriazole, is a proven corrosion inhibitor for copper and copper-based alloys. G-6 functions by reacting with surface copper oxides to form a strong, insoluble polymeric complex. This complex creates a protective layer or film on the copper surface, 10- to 20- molecule thick, that provides both a mechanical and electrochemical barrier against corrosive attack.

This protective layer has a high degree of thermal and oxidative stability and cannot be easily removed. G-6 complexes copper ions in solution, thereby preventing galvanic corrosion of other metals in contact with copper.