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; potassium hydroxide; peroxides of sodium or potassium 28 15 20 Potassium hydroxide (caustic potash) 28 15 20 00 Potassium hydroxide (caustic potash) Commodity Code Description 28 15 20 00 000 Potassium hydroxide (caustic potash)