BS EN 12329:2000 specifies requirements for electrodeposited coatings of zinc on iron or steel with supplementary treatment.
Electrodeposited coating of zinc is chromate treated in order to retard the formation of corrosion products on surfaces of coatings exposed to corrosive atmospheres. When corrosion protection is the main purpose of the coating, the usual practice is to apply a chromate or other conversion coating on top of the electrodeposited zinc coating. This is effective in retarding the formation of white corrosion products which form on zinc coatings under certain conditions.
This European Standard does not specify chromate finishes which are required only for improving the adhesion of paints or v\varnishes.