Hydrochloric acid (HCl)is a colorless solution with a distinctive pungent smell and classified as a strong acid. It is used in many industrial processes such as refining metal and used in the chemical industry as a chemical reagent in the large-scale production of vinyl chloride for PVC plastic and MDI/TDI for polyurethane. It has numerous smaller-scale applications including household cleaning, production of gelatin and other food additives, descaling and leather processing. It is used in the production of chlorides, fertilizers and dyes, in electroplating, and in the photographic, textile and rubber industries.