Section 06 Products of the chemical or allied industries 28 Inorganic chemicals; organic or inorganic compounds of precious metals, of rare-earth metals, of radioactive elements or isotopes 28 15 Sodium hydroxide (caustic soda); potassium hydroxide (caustic potash); peroxides of sodium or potassium. 28 15 20 Potassium hydroxide (caustic potash) Commodity Code Description 28 15 20 00 Potassium hydroxide (caustic potash)