Sodium hydroxide (caustic soda); potassium hydroxide (caustic potash) peroxides of sodium or potassium

281511 Sodium hydroxide (caustic soda); solid 281512 Sodium hydroxide (caustic soda); in aqueous solution (soda lye or liquid soda) 281520 Potassium hydroxide (caustic potash) 281530 Peroxides of sodium or potassium