Cosmetic Preservatives Explained: Annex V (UK & EU)

Preservatives protect cosmetics from the bacteria, yeasts and moulds that would otherwise turn a safe product into a health hazard. But you cannot use just any preservative only those on Annex V of the cosmetic regulation, within their set limits. This guide explains how cosmetic preservation works, which products need it, and how to choose a compliant system.

Annex V is one of the positive lists covered in our pillar guide to cosmetic ingredient annexes. Here we focus on preservatives.

What is Annex V?

Annex V is the positive list of preservatives permitted in cosmetics. Only substances on this list may be used to preserve a product, and each entry sets a maximum concentration and any conditions of use for example limits in particular product types, or restrictions in products for young children. Because it is a positive list, the rule is strict: if a preservative is not on Annex V, it cannot be used as a preservative, however well it works.

This is a deliberately cautious approach. Preservatives are biologically active by design they have to kill microbes so their use on skin is tightly controlled. The list is reviewed regularly, and limits are adjusted as new safety evidence emerges.

Why cosmetics need preservatives

Any cosmetic that contains water, or that will have water introduced during use, can grow microorganisms. A cream, lotion, shampoo or toner is essentially a nutrient-rich, watery environment ideal for bacteria and mould. Without an effective preservative system, such products can become contaminated within days or weeks, posing a real risk of infection, especially around the eyes or on broken skin. Preservation is not an optional extra for these products; it is a safety requirement.

This is why “preservative-free” is a misleading selling point for water-based products. A genuinely water-containing cosmetic with no preservative system is not purer it is unprotected, and likely unsafe by the time it reaches a customer's bathroom. The goal is an effective, compliant preservative used at the right level, not no preservative at all.

Anhydrous products: the exception

Products with no water anhydrous formulations such as balms, body butters, facial oils and many lip products generally do not support microbial growth in the same way, because microbes need water to thrive. These products often do not require a traditional preservative, though they may still benefit from an antioxidant to slow the oils going rancid. This is a different job from preservation and should not be confused with it.

The crucial caveat is that the moment water is introduced a customer dipping wet fingers into a balm, or you adding any water-based ingredient the picture changes. Adding water to an anhydrous product turns it into something that needs preserving. We explain that tipping point in the context of formulating and the CPSR.

Choosing a compliant preservative system

Selecting a preservative means balancing several things: it must be on Annex V and used within its limit, it must be effective against the full range of microbes (broad spectrum bacteria, yeast and mould), and it must be compatible with the rest of your formula, including its pH. Many makers use a well-characterised preservative such as those based on phenoxyethanol or other listed systems, often as part of a blend designed to cover the full spectrum.

Compatibility matters because a preservative can be deactivated by the wrong pH or by certain other ingredients, leaving a product that looks preserved on paper but is not protected in practice. Choosing the system is a formulation decision that the safety assessment then has to confirm actually works.

Proving preservation works: the challenge test

Listing a preservative is not enough you have to show it actually protects the product. This is done with a challenge test (preservative efficacy test), in which the product is deliberately inoculated with microorganisms and monitored to confirm the preservative system controls them. It is a key piece of evidence for water-containing products and feeds directly into the safety assessment in Part B of the CPSR.

We cover this testing in depth in our dedicated guide, but the headline is simple: for a water-based product, a challenge test is how you prove your preservative choice does its job. It is not a formality but a genuine safety check, and it can reveal that a system which looked fine on paper needs adjusting.

Natural and 'self-preserving' claims

Many makers want to avoid conventional preservatives for marketing reasons, and reach instead for ingredients described as “natural preservatives” or formulate what they hope is a “self-preserving” product. This is an area where good intentions often outrun the science. Some natural ingredients do have antimicrobial properties, but few are reliable, broad-spectrum preservatives at usable levels, and several are not even listed on Annex V for use as preservatives which means they cannot be relied on or labelled as performing that function.

“Self-preserving” formulations relying on low water activity, low or high pH, or other hurdles rather than a preservative can be legitimate, but they are genuinely difficult to get right and must be proven, not assumed. A product is only self-preserving if a challenge test demonstrates it actually resists contamination. Declaring a product preservative-free and hoping for the best is not a strategy; it is a recall waiting to happen.

The honest position is that for most water-containing products, a well-chosen, compliant preservative system is the safe and responsible choice. There is nothing unnatural or alarming about protecting your customers from contamination and a contaminated “natural” product helps no one. If you want to minimise preservatives, the route is careful formulation plus robust testing, not wishful thinking.

Preservative compliance checklist

• Use only Annex V listed preservatives, within their limits.

• Preserve any water-containing product with a broad-spectrum system.

• Check pH and ingredient compatibility so the preservative stays active.

• Treat anhydrous products differently antioxidant, not preservative.

• Remember that adding water creates a need to preserve.

• Prove it works with a challenge test feeding your CPSR.

Frequently asked questions

Which preservatives can I use in cosmetics?

Only those listed in Annex V of the cosmetic regulation, within their maximum concentrations and conditions. A preservative not on Annex V cannot be used to preserve a cosmetic.

Do all cosmetics need a preservative?

No only those containing water or that will have water introduced in use. Anhydrous products such as balms and oils generally do not need a traditional preservative, though they may use an antioxidant.

Is 'preservative-free' safe for a water-based product?

Generally no. A water-containing product with no preservative system is unprotected against microbial growth and is likely unsafe by the time it is used. The aim is an effective, compliant preservative, not none.

What happens if I add water to a balm or butter?

It becomes a product that can grow microbes and therefore needs a preservative system and a challenge test. Adding water changes an anhydrous product's preservation requirements entirely.

How do I prove my preservative works?

With a challenge test (preservative efficacy test), which inoculates the product with microbes to confirm the system controls them. The result feeds into Part B of your CPSR.

Are natural preservatives allowed?

Only if they are listed on Annex V for use as a preservative and used within their conditions. Many natural antimicrobials are not listed as preservatives and cannot be relied on or labelled as performing that function.

Can a product really be 'self-preserving'?

Sometimes, through low water activity, pH or other hurdles but only if a challenge test proves it resists contamination. It must be demonstrated, never assumed, and most water-based products are safer with a compliant preservative system.

References: Regulation (EC) No 1223/2009, Annex V (EUR-Lex); ISO 11930 (preservative efficacy testing); UK Cosmetics Regulation as retained. General information only, not legal advice.