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Cleansers

Skin cleansers are cosmetic products whose principal function, in the words of EU cosmetic law, is to clean the external parts of the human body. Behind that simple definition sit a series of formulation choices — surfactant class, pH, vehicle — that distinguish the cleansing products sold in parapharmacies.

Regulatory class

Cleansing products applied to the skin, hair or oral mucosa are cosmetic products within Article 2 of Regulation (EC) No 1223/2009, falling within the function "cleaning". They are subject to the general regime of the Cosmetic Regulation: responsible person, CPNP notification, safety assessment, INCI labelling, and the Annex restrictions on substances. Cleansers that include claims to treat skin disease, or contain pharmacologically active substances above thresholds that re-classify the product, would become medicinal products and fall outside cosmetic law.

Surfactant classes

The active cleansing agent in a skin cleanser is a surfactant — a molecule with a polar (water-loving) head and a non-polar (oil-loving) tail. Surfactants used in cosmetic cleansers fall into four broad classes:

• Anionic surfactants — negatively charged polar heads (for example, sulfates, sulfonates, soaps). Strong cleansers but can be harsh.
• Non-ionic surfactants — uncharged polar heads (for example, alkyl polyglucosides). Generally milder.
• Amphoteric surfactants — heads carrying both positive and negative charges depending on pH (for example, cocamidopropyl betaine). Used as secondary surfactants to modify foam and mildness.
• Cationic surfactants — positively charged heads. Rarely used as primary cleansers in skincare because of skin-interaction profile; more common in hair conditioners.

Soap versus syndet

A "soap" in the technical sense is the salt of a long-chain fatty acid: it is made by saponification of fats with sodium or potassium hydroxide. Traditional soap bars are usually alkaline (pH typically around 9–10) by virtue of this chemistry.

A "syndet" (synthetic detergent) bar is formulated with synthetic surfactants instead of fatty-acid soaps; it can therefore be formulated to a pH closer to that of the skin surface (around 5.5). The product still functions as a cleanser, but with a different surfactant profile and a different impact on the skin's acid mantle. The term "soap-free" on a label is not a regulated term in EU cosmetic law; in industry usage it generally means that the product is built on synthetic surfactants rather than fatty-acid soaps. Consumers should not read "soap-free" as a guarantee of mildness in absolute terms.

pH

Healthy skin surface has an acidic pH, typically described in the dermatological literature as between 4.5 and 6. Cleansers vary widely: traditional soaps tend to be alkaline; syndet bars and liquid cleansers can be formulated to be acidic, neutral or alkaline depending on the surfactant system. Whether a more skin-pH-matched cleanser is better tolerated than an alkaline one in any given user is a question of formulation as a whole, not just of pH; cleansers must in any case comply with the general cosmetic safety requirement under Article 3 of the Regulation.

Micellar formulations

Micellar waters are cleansers in which surfactant molecules are present at a concentration above their critical micelle concentration (CMC), forming micelles — spherical assemblies that solubilise oils and make-up residues. They are typically rinse-free in normal use and are positioned for facial cleansing and make-up removal. The cosmetic regulatory status of a micellar water is the same as any other facial cleanser: a cosmetic product under Regulation 1223/2009.

What labels do and do not tell you

The INCI ingredients list, mandatory under Article 19 of the Regulation, identifies the surfactants used, in descending order of weight down to 1% and in any order below 1%. Functional terminology on the front of the pack ("soap-free", "syndet", "ultra-rich", "for sensitive skin") is not generally a regulated cosmetic term. Sensitive-skin claims and tolerance claims must comply with the common criteria of Commission Regulation (EU) No 655/2013, which require evidential support and prohibit misleading claims. Specific medical claims (treatment of disease) are forbidden on cosmetics.

For consumers

This site does not provide product recommendations. The general label-literacy points above are intended to support understanding of what a cleanser is and is not. For questions about cleansing routines in the context of a specific skin condition, the appropriate advice is from a pharmacist or a physician.

Last reviewed: May 2026.