Section 06 PRODUCTS OF THE CHEMICAL OR ALLIED INDUSTRIES 28 Inorganic chemicals; organic or inorganic compounds of precious metals , of rare 28 15 Sodium hydroxide (caustic soda); potassium hydroxide (caustic potash); peroxides 28 15 11 28 15 11 00 Commodity Code Description 28 15 11 00 00 -- Solid 28 15 12 00 00 -- In aqueous solution (soda lye or liquid soda) 28 15 20 00 00 - Potassium hydroxide (caustic potash) 28 15 30 00 00 - Peroxides of sodium or potassium