Section 06 Products of the chemical or allied 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 11 - - Solid 28 15 11 00 - - Solid Commodity Code Description 28 15 11 00 000 - - Solid