Preservatives in cosmetics: phenoxyethanol, sodium benzoate and what “preservative-free” really means
Any cosmetic that contains water needs protection against bacteria, yeasts and moulds. What phenoxyethanol, sodium benzoate, potassium sorbate and ethylhexylglycerin do, and how a product can honestly be “preservative-free”.
Updated: 31 October 2026 · Reviewed by: Kamil Pyziak
Why cosmetics need preserving at all
Water, sugars, proteins and plant extracts are food not only for skin but also for microorganisms. A cream or shampoo is opened dozens of times, touched with fingers and kept in a warm, humid bathroom, so without protection it can become contaminated within weeks. Contamination is not just a cosmetic problem: it can change the texture and smell of a product and, in rare cases, put the user at risk of infection, especially around the eyes.
For this reason, in the EU a substance whose main purpose is to inhibit the growth of microorganisms in the product may only be used if it appears on the list of permitted preservatives in Annex V of the Cosmetics Regulation (EC) No 1223/2009. Each entry has a maximum concentration and, for some substances, extra conditions. The manufacturer must also show in the safety assessment that the finished product is adequately protected, usually through a so-called challenge test.
Phenoxyethanol: the most common preservative today
Phenoxyethanol is a glycol ether – a clear, slightly oily liquid with a faint rosy smell. It is effective mainly against bacteria and is found in creams, serums, shampoos, wet wipes and make-up. In Annex V its maximum concentration in the finished product is 1%. In practice it is often used below that level and combined with other ingredients to widen its spectrum of activity.
Its popularity grew when many brands moved away from parabens. Phenoxyethanol has been reviewed by the EU Scientific Committee on Consumer Safety (SCCS), which considered it safe at the permitted maximum. Like any ingredient, it can occasionally irritate sensitive skin, but allergy to it is considered uncommon.
Sodium benzoate and potassium sorbate: the food-grade pair
Sodium Benzoate and Potassium Sorbate are the salts of benzoic acid and sorbic acid, both also used as food preservatives (E211 and E202). In cosmetics they are popular in products marketed as natural, because they are accepted by many natural and organic certification standards. Annex V sets their limits calculated as the free acid; for benzoic acid and its salts the limit differs between rinse-off products, oral care and leave-on products, while for sorbic acid and its salts it is 0.6%.
Both work best in acidic formulas, because it is the undissociated acid form that is active against microorganisms. They are stronger against yeasts and moulds than against bacteria, so they are usually combined with each other or with other ingredients. In a formula with a near-neutral pH they would need support, which is why you often see them next to an acidifier such as Citric Acid.
Ethylhexylglycerin and other “helpers”
Ethylhexylglycerin is not on the EU list of preservatives; its official functions are skin conditioning and deodorant. It is, however, very often paired with phenoxyethanol, because it makes microorganisms more sensitive to the preservative and allows a lower dose to work. Ready-made blends of the two are common, which is why they so often appear side by side on INCI lists.
A similar role is played by ingredients such as Caprylyl Glycol, 1,2-Hexanediol, Pentylene Glycol or Glyceryl Caprylate. They are used as emollients, humectants or solvents, and as a side effect they make life harder for microbes. Because their main declared function is not preservation, they are not subject to Annex V. Dehydroacetic Acid and Benzyl Alcohol, by contrast, are listed preservatives; benzyl alcohol is also a fragrance component.
What “preservative-free” can actually mean
Some products genuinely need no added preservative. Anhydrous products – oils, balms, lipsticks, powders, solid soaps – contain no free water and are much harder for microbes to colonise. Products with a high content of ethanol or glycols, single-dose ampoules and airless pumps that prevent backflow can also reduce or remove the need for a classic preservative.
In other cases “preservative-free” means that the formula relies on multifunctional ingredients that are not officially preservatives, such as the glycols mentioned above. Microbiologically the product is still protected, just not by an Annex V substance. EU rules on cosmetic claims require claims to be truthful and not misleading, and guidance on “free from” claims takes a critical view of statements that suggest a product is unprotected when other ingredients do the job. In practice, read the INCI list rather than the front of the pack.
What the label does not tell you
The INCI list shows which preservatives are present, but not their concentration or how well the system performed in the challenge test. A product with no recognisable preservative is not automatically gentler: if the protection is too weak, contamination is the bigger risk.
The open-jar symbol with a number of months (period after opening) tells you how long the product should be used once opened. Keep jars closed, avoid adding water and use a spatula where possible. If a product changes smell, colour or texture, stop using it. If you react to a preservative, a dermatologist can identify the exact substance with patch testing.