Sodium hydroxide (caustic potash), CON - hydroxide potassium. White solid, temperature melting 380,49. Used in the production of liquid soap and as a reagent in laboratories. Strong alkali. On properties and on the effects on the skin and mucous membranes similar to sodium hydroxide. First aid for poisoning and lesions of the skin - see Caustic soda, Poisoning, caustic alkalis. Cm. also Alkalis.