SECTION VI - PRODUCTS OF THE CHEMICAL OR ALLIED INDUSTRIES > CHAPTER 28 - INORGANIC CHEMICALS; ORGANIC OR INORGANIC COMPOUNDS OF PRECIOUS METALS, OF RARE-EARTH METALS, OF RADIOACTIVE ELEMENTS OR OF ISOTOPES > IV. INORGANIC BASES AND OXIDES, HYDROXIDES AND PEROXIDES OF METALS > 2815 Sodium hydroxide (caustic soda); potassium hydroxide (caustic potash); peroxides of sodium or potassium > Peroxides of sodium or potassium