surface treatment chemicals and conditioners for cleaning metals, plastics, glasses and ceramics before they are painted, consisting of chlorinated hydrocarbons, or caustics and acids; namely, hydrochloric and sulfuric; surface conditioning, sealing and passivating chemicals for preparing metallic surfaces before they are painted, consisting of chromate conversion coatings, or dichromate solutions, or sodium dichromate and sulfuric acid mixtures, or chromate solutions, or phosphate solutions,...