6 CHEMICAL COMPOUNDS, OPAQUING AGENTS, AND PIGMENTS USED IN THE MANUFACTURE OF ENAMELS AND GLAZES; AND TITANIUM, MIXTURES CONTAINING TITANIUM, TITANIUM COMPOUNDS, MIXTURES CONTAINING TITANIUM COMPOUNDS, ZIRCONIUM, MIXTURES CONTAINING ZIRCONIUM, ZIRCONIUM COMPOUNDS, MIXTURES CONTAINING ZIRCONIUM COMPOUNDS