Facial cleanser-also known as cleansing milk or face wash-falls under the category of cosmetic cleansing products.
It is used to remove surface impurities from facial skin, leaving the skin feeling fresh and comfortable. By helping to maintain the skin's normal physiological functions, it typically serves as the foundational first step in any skincare routine.
When a facial cleanser is used to cleanse the skin, the object of the cleansing action (i.e., the substrate) is the human skin itself. The impurities adhering to the skin primarily consist of sebum, fragments of the stratum corneum (dead skin cells), and their oxidized breakdown products; alternatively, these impurities may be cosmetic residues that have become bound to the skin's surface. These residual metabolic byproducts are inherently unstable and can react with atmospheric oxygen or with deposited molecules. When exposed to sunlight-or in the presence of bacteria on the skin-various physicochemical and biochemical reactions may occur, potentially generating substances that could be harmful to the skin. Consequently, even for individuals with healthy skin, cleansing remains an indispensable process within any comprehensive skincare regimen. Furthermore, for those with sensitive or fragile skin types, the unique characteristics of their skin necessitate specialized cleansing and care. When addressing problematic skin types, it is absolutely essential to prioritize the gentleness and safety of the chosen facial cleanser.
Facial cleansers are classified as facial cleansing products. During the cleansing process, the targets of the cleanser's action include endogenous impurities-such as sebum, sweat, and exfoliated stratum corneum cells secreted by the facial skin-as well as exogenous impurities originating from the external environment, such as dust, various microorganisms, and cosmetic residues. These residual metabolic byproducts are unstable and prone to reacting with atmospheric oxygen or with deposited molecules. When exposed to sunlight-or in the presence of bacteria on the skin-various physicochemical and biochemical reactions may ensue, potentially generating irritants or substances that could cause harm to the skin.
Therefore, even for individuals with healthy skin, cleansing remains an indispensable process within any comprehensive skincare regimen.
Furthermore, consumers should select appropriate cleansing products based on their specific skin type. For those with sensitive or fragile skin types, it is crucial to prioritize the product's gentleness and safety, as such skin requires specialized cleansing and care.
Facial cleansers remove surface impurities from the skin through the actions of surfactants-specifically via wetting, emulsification, or solubilization processes. Additionally, to prevent excessive stripping of natural oils and to ensure skin lubrication, an appropriate amount of emollients and humectants is typically added to the formulation; this ensures effective wetting while leaving the skin feeling soft and supple.
The components typically found in facial cleansers are as follows:
(1) Surfactants (Cleansing Agents)
Primarily serve the functions of cleansing and foaming.
Soap-based systems: Composed of higher fatty acids and alkaline agents.
Other surfactants: Alkyl sulfates, N-acyl methyl taurates, alkyl glucosides, POE alkyl ethers, disodium cocoamphodiacetate, etc.
(2) Humectants
Glycerin, 1,3-butylene glycol, dipropylene glycol, propylene glycol, sorbitol, etc.
(3) Emollients (Lipid Replenishers)
Fatty acids, plant oils (coconut oil, jojoba oil, olive oil, etc.), higher alcohols, lanolin derivatives, etc.; these primarily serve to replenish lipids and provide lubrication.
(4) Other Components
Water-soluble polymers, preservatives, antioxidants, chelating agents, active ingredients, fragrances, etc. Some facial cleansers also contain exfoliating granules.
