The global market for surfactants reached £40.22 million in 2025 and is forecast to reach £60.84 million by 2033, with a compound annual growth rate of 5.4%, according to Grand View Research. These figures are no coincidence: surface-active agents are present in virtually every cleaning and hygiene product we use daily, from shampoo to facial cleanser.
For formulators and cosmetic brands, understanding what they are, how they work and which ones to choose is the first step towards developing safe, effective and competitive products. At Cosmos Aromatica, we guide you through everything you need to know!
What are surfactants and how do they work?
Surfactants are amphiphilic molecules, meaning molecules that simultaneously possess a hydrophilic head (affinity for water) and a hydrophobic tail (affinity for fats and oils). This dual chemical nature is what allows them to act as bridges between two phases that would otherwise not mix: water and lipids.
When a surfactant is added to a liquid, it positions itself at the interface between the two phases and reduces the surface tension — that is, the force that holds water molecules together at their surface. By lowering this tension, the liquid wets surfaces more effectively, penetrates fabrics more readily and can carry fat and dirt particles away during rinsing.
Above a certain concentration — known as the critical micelle concentration (CMC) — surfactant molecules cluster into spherical structures called micelles: the hydrophobic tail is encapsulated in the interior, away from the water, whilst the hydrophilic head points outwards. The micelles trap fat particles in their core and keep them in suspension in the water, facilitating their removal during rinsing.
This mechanism underpins all cleansing formulation ingredients: the shampoo that cleanses the scalp, the shower gel that removes sebum, or the facial cleanser that removes make-up — all work thanks to the action of one or more combined surface-active agents.
Types of surfactants: classification and key characteristics
Surfactants are classified into four main groups according to the electrical charge of their hydrophilic head. Each type presents a different performance profile, skin tolerance and compatibility, which determines its optimal use in cosmetic formulation.
Anionic surfactants
Anionic surfactants carry a negative charge on their hydrophilic head. They are the most widely used in the industry owing to their exceptional foaming capacity and deep-cleansing power. Among their best-known representatives in INCI nomenclature are Sodium Lauryl Sulfate (SLS) and Sodium Laureth Sulfate (SLES), commonly found in volumising shampoos and general-purpose cleaning products.
Their main limitation is the potential for irritation in sensitive or atopic skin, which is why many modern formulations combine them with softening co-surfactants or replace them entirely with better-tolerated alternatives.
Non-ionic surfactants
Non-ionic surfactants carry no electrical charge, which gives them a high compatibility with other cosmetic ingredients and outstanding skin tolerance. They form the basis of products labelled as ‘sulphate-free’. In INCI nomenclature, notable examples include Decyl Glucoside, Coco Glucoside and Polysorbate 20. Their mildness makes them particularly well suited for use in shampoo formulations for sensitive scalps, baby cosmetics and daily-use facial cleansers.
Amphoteric surfactants
Amphoteric surfactants carry a charge that varies according to the pH of the medium: they behave as anionic at alkaline pH and as cationic at acidic pH. This versatility gives them excellent skin tolerance and conditioning properties. The most representative example in cosmetics is Cocamidopropyl Betaine (cocamidopropyl betaine), widely used as a co-surfactant in shower gel formulations and shampoos, where its primary role is to soften the detergent base and improve the tactile feel during rinsing.
Cationic surfactants
Cationic surfactants carry a positive charge and are notable for their conditioning, antistatic and antimicrobial properties. As they carry a charge opposite to that of hair fibres and skin (which carry a negative charge), they adhere to them readily and deposit a protective film. The most commonly used in cosmetics carry INCI names such as Behentrimonium Chloride and Cetrimonium Chloride, found in conditioners, hair masks and softening emulsions.
| Type | Charge | INCI Example | Primary Use | Mildness Profile |
|---|---|---|---|---|
| Anionic | Negative | Sodium Lauryl Sulfate, Sodium Laureth Sulfate | Shampoos, gels, cleansers | Low–medium (irritating at high concentrations) |
| Non-ionic | Neutral | Decyl Glucoside, Coco Glucoside, Polysorbate 20 | Sulphate-free cosmetics, baby, facial | High |
| Amphoteric | Variable (pH-dependent) | Cocamidopropyl Betaine | Co-surfactant in shampoos and gels | Very high |
| Cationic | Positive | Behentrimonium Chloride, Cetrimonium Chloride | Conditioners, hair treatments | High (conditioning) |
What is the difference between a surfactant and a detergent?
Confusion between these two terms is common amongst consumers and novice formulators alike. The distinction is clear: a surfactant is the active ingredient of a chemical nature that possesses the hydrophilic–hydrophobic dual nature described above. A detergent, on the other hand, is the formulated and commercially available product containing one or more surfactants as its principal components, together with other builders (agents that counteract water hardness), preservatives, fragrances, colourants and pH-adjusting agents.
The relationship between the two concepts can be summarised with a simple analogy: a surfactant is to a detergent what flour is to bread. Without flour there is no bread, but bread also requires yeast, water, salt and the baker’s skill to take its final shape. In the same way, the surfactant is the functional raw material, but the detergent is the result of a complete formulation.
This distinction is explicitly recognised in European legislation. The European Chemicals Agency (ECHA) and EUR-Lex precisely distinguish the concept of ‘surfactant’ from that of ‘detergent’ within the framework of Regulation (EC) 648/2004, establishing separate legal definitions for each.
Are surfactants biodegradable and safe for the environment?
The answer depends largely on the type of surfactant and its origin. It is worth distinguishing two key concepts that European legislation also differentiates with precision.
Primary biodegradability occurs when a surfactant loses its surface activity, even though the molecule has not yet fully broken down. Total or ultimate biodegradability — also known as mineralisation — occurs when the molecule breaks down completely into carbon dioxide, water and mineral salts, leaving no persistent metabolites. Regulation (EC) 648/2004, available in full on EUR-Lex, requires all surfactants marketed in the European Union to meet ultimate biodegradability criteria — not merely primary biodegradability — representing a significantly higher level of environmental stringency than in previous decades.
In terms of environmental profile, plant-based surfactants — derived from coconut oil, certified palm oil or maize sugars — generally present lower ecotoxicity and faster biodegradability than their petrochemical synthesis equivalents. Biosurfactants, produced by micro-organisms through fermentation processes — such as rhamnolipids or sophorolipids — represent the most sustainable frontier of this ingredient family. According to Grand View Research, the bio-based surfactant segment is the fastest-growing within the global market, with a projected CAGR of 5.8% through to 2033.
This trend has driven the growth of so-called eco-friendly surfactants, certified under standards such as COSMOS or ECOCERT, whose market share in Europe continues to grow year on year, particularly in the personal care and natural cosmetics categories.
Surfactants in cosmetic formulation: key factors for choosing the right one
Selecting the right surfactant for a formulation is not an arbitrary decision. Multiple technical and commercial factors need to be assessed from the outset of the development process. The following are the five fundamental criteria that every formulator should consider:
- Formulation pH. Some surfactants, such as amphoteric ones, are sensitive to pH fluctuations. Anionic surfactants generally work well across acidic-to-neutral ranges, whilst non-ionic surfactants are particularly stable under extreme conditions.
- Target skin type. Sensitive, atopic or infant skin requires mild surfactants — non-ionic or amphoteric — with a low irritation index. Formulations for oily skin or body care may better tolerate anionic surfactants.
- Functional objective. Does the formulation prioritise deep cleansing, dense foam generation, residual moisturisation or conditioning action? Each objective calls for a different type or combination of surfactants.
- Compatibility with other actives. Cationic surfactants are incompatible with anionic ones if not formulated correctly. Essential oils, preservatives and colourants may also be affected by the choice of base surfactant.
- Applicable certification and regulation. If the final product aims for COSMOS, ECOCERT certification or must comply with Regulation (EC) 1223/2009 on cosmetic products, the origin and composition of the surfactant are non-negotiable constraints from the design stage onwards.
- At Cosmos Aromatica, we offer a selection of natural surfactants and synthetic alternatives for all types of formulations: from mild, plant-based surfactants for certified cosmetics through to high-performance foaming bases for conventional cleansing formulations.
Frequently asked questions about surfactants
Which is the mildest surfactant for sensitive skin?
Decyl Glucoside and Cocamidopropyl Betaine are amongst the best-tolerated surfactants for sensitive skin. They are of plant origin — non-ionic and amphoteric respectively — and present a very low irritation index. At Cosmos Aromatica, we routinely use them as the base in formulations for baby products and dermatological cosmetics.
Are natural surfactants as effective as synthetic ones?
Generally speaking, yes — though with some nuances. The latest generation of natural surfactants — such as alkyl glucosides — offer a cleansing capacity comparable to conventional ones, with the added benefit of a better skin tolerance profile and biodegradability. The key lies in the usage concentration and the appropriate combination of types within the same formula.
Can I combine different types of surfactants in the same formulation?
Yes, and in fact this is common practice in professional formulation. Combining an anionic surfactant with an amphoteric one — such as SLS or SLES with Cocamidopropyl Betaine — improves mildness and tactile feel without sacrificing cleansing power. The only critical restriction is to avoid directly mixing cationic and anionic surfactants without the appropriate formulation precautions.
Which surfactants are prohibited or restricted in cosmetics in the EU?
Regulation (EC) 1223/2009 on cosmetic products and its subsequent updates set out the lists of prohibited and restricted ingredients applicable in the EU. Certain cationic surfactants with biocidal properties are subject to concentration restrictions. We always recommend consulting the CosIng database of the European Commission to verify the regulatory status of any surfactant before incorporating it into a formula.
Formulate with purpose: the right surfactant makes all the difference
A thorough understanding of surfactants — their chemistry, classification and environmental implications — is a genuine competitive advantage for any formulator or cosmetic brand. Choosing the right base surfactant for a product is no minor detail: it determines the product’s efficacy, skin tolerance, sustainability profile and regulatory viability in the European market. The earlier this knowledge is integrated into the development process, the fewer revisions are needed and the more coherent the final formula.
At Cosmos Aromatica, we have a technical team ready to work on new formulas tailored to your needs and to become your trusted supplier. Get in touch with us: we will assess your requirements and guide you through the next steps.