Potassium hydroxide is a commonly used chemical raw material, classified as an inorganic alkali. We often find it listed in the ingredient labels of facial cleansers. So, what is the specific role of potassium hydroxide in facial cleansers?
Facial cleansers are cleansing agents designed to remove facial dirt, oil, dead skin cells, oxidation products, and residual makeup. Potassium hydroxide is added to facial cleansers because when it reacts with the oil content, it promotes hydrolysis of the oil. This reaction results in the formation of potassium fatty acids, which then neutralize with the hydrolyzed acids, effectively removing dirt. The potassium hydroxide content in facial cleansers is generally not very high, so it can be used safely.
Potassium hydroxide is an important raw material in the cosmetics industry due to its strong alkaline nature. When it reacts with oil, it forms soap and glycerol. The main component of mature soap is “fatty acid salts,” which act as surfactants with both lipophilic and hydrophilic ends. The lipophilic end binds to peroxidized oils and dirt on the skin, while the hydrophilic end binds to water during rinsing, carrying away the dirt. Therefore, it serves the purpose of cleansing.
