1. The zipper should be tested prior to the bulk production in case the content of the heavy metal cadmium exceeds the standard.
2. Avoid exposure to the damp environment. The metal teeth will get black due to the metal oxidization and dip-dyeing that take place.
3. Avoid direct contact with the rubber band. Sulfuration will happen to the metal teeth if the metal zippers are tied with a rubber band which contains sulfide.
4. The zipper should be cleaned and dried timely after the washing process. Color change may happen to the metal parts due to the redox reaction that takes place between the dyes or residual chemicals in the fabric and the metal parts.