Cosmetic Ingredient Lists & INCI Names Explained (UK & EU)

Every cosmetic sold in the UK or EU must carry a list of ingredients written in a specific, standardised way using INCI names, in the right order, following rules that trip up many new makers. Get it wrong and your product is non-compliant even if it is perfectly safe. This guide explains exactly how to build a correct cosmetic ingredient list.

The ingredient list is one piece of the labelling puzzle; for the full set of mandatory information see our guides to label warnings and mandatory statements and net quantity, batch codes and dates.

What is INCI?

INCI stands for the International Nomenclature of Cosmetic Ingredients a standardised naming system used across the UK, EU and much of the world so that the same ingredient is identified the same way everywhere. Water becomes “Aqua”, olive oil becomes “Olea Europaea (Olive) Fruit Oil”, and shea butter becomes “Butyrospermum Parkii (Shea) Butter”. The point is consistency: a dermatologist, an authority or an allergic consumer anywhere should be able to read any cosmetic's list and know precisely what is in it.

INCI names are not the same as the trade names or marketing names on your supplier's invoice. A supplier might sell you a blend under a brand name, but on your label you must use the correct INCI name for each component. Establishing the right INCI for every ingredient is one of the first jobs in preparing a compliant label, and it is where the underlying ingredient data in your safety documentation becomes invaluable.

Descending order of weight

Ingredients must be listed in descending order of weight as they were added to the formula. The ingredient present in the greatest amount comes first usually water in a lotion, or a base oil in an anhydrous product and the rest follow down to the smallest. This order tells the reader, at a glance, roughly how much of each ingredient the product contains relative to the others, which is useful information for anyone with a sensitivity or a preference.

Getting the order right depends on knowing your exact formula percentages. This is one reason a vague or approximate recipe causes problems: you cannot write a compliant list without knowing what quantity of each ingredient you actually added. Precise formulation is the foundation of both your safety assessment and your label.

A quick example shows how it works. Imagine a simple body lotion that is mostly water, then a plant oil, then an emulsifier, then a humectant, with a preservative and a little fragrance near the end. The list would open with “Aqua”, follow with the oil and emulsifier in the amounts used, then the smaller ingredients, finishing with the preservative, “Parfum” and any named allergens. The reader can see at a glance that the product is water-based and oil-rich, simply from the order which is exactly what descending order is meant to convey.

The 1% rule

There is an important exception to strict descending order. Ingredients present at a concentration of 1% or less may be listed in any order, after those present above 1%. In practice this means the first part of your list is strictly ranked, and the tail end the many minor ingredients each at or below 1% can be arranged more freely. Preservatives, many actives, and fragrance components often sit in this lower portion.

The 1% rule is a convenience, not a loophole: every ingredient still has to appear, and you cannot hide a significant ingredient by misplacing it. The line simply reflects that ranking tiny quantities to the milligram would add little value. Knowing where the 1% threshold falls in your formula helps you order the list correctly.

How to list fragrance and 'Parfum'

A fragrance or essential oil blend is listed using the single term “Parfum” (or “Aroma” for flavour), rather than naming every aromatic component. This recognises that fragrance compositions can contain many constituents. However, this convenience comes with a major condition: certain fragrance allergens must still be declared individually by name when they are present above set thresholds, even though the rest of the fragrance is covered by “Parfum”.

This allergen-declaration requirement is significant and changing, with the list of named allergens having expanded under recent EU rules. Because it is detailed enough to warrant its own treatment, we cover exactly how to handle it in our dedicated guide to labelling fragrance allergens. For now, the key point is that “Parfum” alone is rarely the whole story.

Listing colourants

Colourants are identified by their Colour Index (CI) numbers for example CI 77491 for a red iron oxide rather than common colour names. They are generally listed after the other ingredients. For decorative ranges sold in several shades, such as a lipstick line, the rules allow colourants from the whole range to be listed together using the phrase “may contain” or the “+/-” symbol, so one label can serve multiple shades.

Only colourants permitted for cosmetic use may appear, and some are restricted to certain product types lip and eye products have their own constraints. The CI number ties each colour back to the approved list, which is why craft or food colours without a valid cosmetic CI are a recurring compliance problem.

Nanomaterials and other special cases

Some ingredients carry extra labelling requirements. Ingredients present in nano form must be identified with the word “[nano]” in brackets after the name. Certain ingredients have their own conventions, and components that are themselves mixtures need to be broken down to their relevant constituents. These details are easy to miss but matter for compliance, and they are part of why translating a formula into a correct label benefits from an experienced eye.

The ingredient list also has to be legible and indelible on the finished pack, in the right place, and for some elements in the language of the market. A technically correct list that rubs off or is unreadably small does not meet the requirement.

Where the data comes from

A correct ingredient list is really an output of good underlying data. The INCI names, the percentages that drive the order, the colourant CI numbers and the allergen content all come from your formulation and your suppliers' documentation the same information that feeds your CPSR and Product Information File. When that data is complete and accurate, generating a compliant label is straightforward; when it is patchy, the label is where the gaps show.

This is why labelling is best treated as part of your overall compliance work rather than a last-minute design task. The safety assessment and the label draw on the same source of truth about what is in your product.

Common ingredient-list mistakes

A handful of errors account for most non-compliant ingredient lists. The most common is using trade or marketing names instead of INCI writing “vitamin E” rather than “Tocopherol”, or a supplier's brand name for a blend rather than its constituent INCI names. The second is getting the order wrong, usually because the maker does not know their exact percentages and guesses, placing ingredients too high or too low. The third is omitting fragrance allergens that must be named individually, leaving only “Parfum” when declarable allergens are present above threshold.

Other frequent slips include forgetting the [nano] marker where it applies, listing colourants by colour name rather than CI number, and producing a list that is technically correct but printed too small or in a place where it rubs off. None of these mistakes mean a product is unsafe but each one makes it non-compliant, and each is exactly the kind of thing a marketplace check or Trading Standards inspection picks up quickly. The fix in every case is the same: accurate ingredient data and a careful translation of the formula into the list.

Cosmetic ingredient list checklist

• Use correct INCI names for every ingredient.

• List in descending order of weight, with the 1% rule for minor ingredients.

• Use “Parfum”/“Aroma” for fragrance, plus named allergens above threshold.

• List colourants by CI number, using “may contain”/“+/-” for shade ranges.

• Mark [nano] ingredients and any special cases.

• Ensure the list is legible, indelible and correctly placed.

Frequently asked questions

What are INCI names?

INCI (International Nomenclature of Cosmetic Ingredients) is a standardised naming system used across the UK, EU and beyond, so each ingredient is identified the same way everywhere for example Aqua for water and Parfum for fragrance.

What order do cosmetic ingredients go in?

In descending order of weight as added to the formula. Ingredients at 1% or less may be listed in any order after those above 1%.

How do I list fragrance on a cosmetic label?

Use the single term Parfum (or Aroma for flavour), but you must also name individual fragrance allergens present above the relevant threshold.

How are colourants listed?

By their Colour Index (CI) numbers, generally after other ingredients. Decorative ranges can list shade colourants together using 'may contain' or the '+/-' symbol.

Can I use ingredient trade names on the label?

No. The label must use the correct INCI name for each ingredient, not the supplier's trade or marketing name.

References: Regulation (EC) No 1223/2009, Articles 19 and 33 (EUR-Lex); EU CosIng database for INCI; UK Cosmetics Regulation as retained. General information only, not legal advice.