Potassium hydroxide is commonly known as caustic potassium, potassium ash, etc., industrial products mainly have two forms, respectively, solid and liquid, of which solid is white or light gray sheet, block rod, liquid potassium hydroxide is light yellow liquid. Chemical properties and sodium hydroxide similar, has a strong alkaline and corrosive, easy to dissolve in water and will be a lot of heat, and delixing, easy to absorb moisture in the air and delixing, absorb carbon dioxide into potassium carbonate. Large amounts of heat are generated when dissolved in water, alcohol or treated with acid. A 0.1mol/L solution has a pH of 13.5. (No water). Moderately toxic, median lethal dose (rats, orally) 1230mg/kg. At present, potassium hydroxide is mainly used to synthesize potassium carbonate, potassium permanganate, etc., mainly used in chemical industry, food, medicine, agriculture and other fields. Potassium hydroxide can be divided into food grade and industrial grade two, of which industrial grade 99% potassium hydroxide is mainly used in leather, paper, printing and dyeing, sewage treatment and other fields; Food grade potassium hydroxide is mainly used in pharmaceutical intermediates, various potassium salts, food additive ingredients, food processing containers cleaning, disinfection and other fields. Sodium hydroxide and potassium hydroxide are raw materials for manual soap, both of which are strong alkali, but after the completion of manual soap, its alkalinity will continue to decline because of the saponification of oil and grease, and after 1-2 months, its alkalinity will be reduced to even less than 9, which will not cause major damage to the skin.