It is harmful to some extent, but the reaction of potassium hydroxide mixed with oil can promote the hydrolysis of oil and neutralize the reaction with the acid attack after hydrolysis. Alkali is necessary for making cleaning products. Potassium hydroxide is used for making liquid soap and sodium hydroxide is used for solid soap. They are all alkali. Soap and glycerol are formed after alkali and oil react. The main component of mature soap is "high fatty acid salt", which is a surfactant with hydrophilic and lipophilic ends. The hydrophilic end separates the peroxide oil and dirt from the skin. When flushing, the hydrophilic end separates the dirt from the water and thus cleans the skin. This is the cleaning principle of solid soap or liquid soap.
氢氧化钾的化学式：KOH， 式量：56.1白色粉末或片状固体。 熔点380℃，沸点1324℃， 相对密度2.04g/cm 3， 折射率n20/D1.421， 蒸汽压1mmHg（719℃）。具强碱性及腐蚀性。极易吸收空气中水分而潮解，吸收二氧化碳而成碳酸钾。溶于约0.6份热水、0.9份冷水、3份乙醇、2.5份甘油。当溶解于水、醇或用酸处置时产生大量热量。0.1mol/L溶液的pH为13.5。中等毒，半数致死量（大鼠，经口）1230mg/kg。溶于乙醇，微溶于醚。有极强的碱性和腐蚀性，其性质与烧碱类似。中等毒， 半数致死量（大鼠，经口）1230mg/kg。！
Chemical formula of potassium hydroxide: KOH, formula amount: 56.1 white powder or flake solid. Melting point 380 C, boiling point 1324 C, relative density 2.04g/cm 3, refractive index n20/D1.421, vapor pressure 1 mmHg (719 C). Strong alkalinity and corrosiveness. It is easy to absorb water in the air and deliquescence, and absorb carbon dioxide to form potassium carbonate. Soluble in about 0.6 parts of hot water, 0.9 parts of cold water, 3 parts of ethanol, 2.5 parts of glycerol. When dissolved in water, alcohol or treated with acid, a large amount of heat is generated. The pH of 0.1 mol/L solution is 13.5. Moderate toxicity, half lethal dose (rat, oral) 1230 mg/kg. Soluble in ethanol, slightly soluble in ether. It has strong alkalinity and corrosiveness, and its properties are similar to those of caustic soda. Moderate toxicity, half lethal dose (rat, oral) 1230 mg/kg.
Potassium hydroxide is effective for a long time in sealed storage.
Potassium hydroxide is afraid that water will break down! Fear of opening up, because it will absorb carbon dioxide in the air, into potassium carbonate!
Overheating: It will react with the glass to produce potassium silicate and impurities.
So it only needs to be kept in closed storage, and there is no problem of shelf life. If the bag is broken, it is advisable to use it as soon as possible.