INCI Ingredient Lists for Cosmetics: How to Write, Order, and Display Them Correctly

INCI stands for International Nomenclature of Cosmetic Ingredients — the standardised naming system used for cosmetic and personal care ingredients worldwide. An INCI-compliant ingredient list is legally required on every cosmetic product sold in the United States, European Union, United Kingdom, Canada, and most other major markets.

Getting the ingredient list wrong is not a minor issue. Non-compliant labelling exposes brands to FDA warning letters, EU market withdrawal, retailer rejection, and civil liability if a consumer has an allergic reaction to an undisclosed or mislabelled ingredient.

What INCI Names Are

Before the INCI system, ingredients had different names in different countries and different industries. Retinol was called Vitamin A in some contexts and beta-carotene adjacent structures in others. The same plant extract was named differently by different suppliers. This created confusion in international trade and made ingredient transparency meaningless.

The INCI system, developed by the Personal Care Products Council (PCPC) in the US and coordinated internationally, assigns a single standardised name to each cosmetic ingredient. These names are not common names or brand names — they are technical designations that follow specific nomenclature conventions:

• Synthetic chemicals use their IUPAC (International Union of Pure and Applied Chemistry) names, often shortened. For example, the INCI name for propylene glycol is simply "Propylene Glycol."
• Botanical ingredients use a Latinised binomial name (genus species) followed by the plant part and preparation. For example, aloe vera gel is "Aloe Barbadensis Leaf Juice" in INCI nomenclature.
• Trademarked or proprietary materials may have INCI names that describe their composition rather than their trade name. A supplier's "HydraComplex™" might be listed as a combination of INCI names in the ingredient declaration.

The authoritative source for INCI names is the International Cosmetic Ingredient Dictionary and Handbook, published by the PCPC. In the EU, the Cosmetic Ingredient Database (CosIng) maintained by the European Commission is the official reference.

The Ingredient Order Rule

In every major market, cosmetic ingredients must be listed in descending order of concentration by weight (or volume, for liquids). The ingredient present in the highest concentration is listed first; the ingredient present in the lowest concentration is listed last.

The 1% threshold rule. Ingredients present at 1% or more by weight must be listed in strict descending order. Ingredients present at less than 1% may be listed in any order after all ingredients at or above 1% are declared. This rule exists because manufacturers often consider the exact concentrations of minor ingredients to be proprietary formulation information — the less-than-1% group can be declared without revealing the precise proportions.

Colourants. In the US, colour additives are listed at the end of the ingredient list regardless of their concentration, in any order. In the EU, colourants may be listed at the end of the list, also in any order, and may optionally be designated with the CI (Colour Index) number (e.g. CI 77891 for titanium dioxide).

Fragrance and flavour. Fragrances and flavours are complex compositions that may contain hundreds of individual chemical ingredients. Both US and EU regulations allow the collective declaration "Fragrance" (US, or "Parfum" in EU/UK) or "Flavor"/"Flavour" in place of the individual fragrance or flavour chemicals. However, the EU Cosmetics Regulation (EC 1223/2009) requires disclosure of 26 specific fragrance allergens when they are present above threshold concentrations (0.001% in rinse-off products, 0.01% in leave-on products). These allergens must be listed individually by INCI name in addition to "Parfum."

The EU Cosmetics Regulation update (adopted 2023, phased implementation) extends the list of fragrance allergens requiring individual disclosure from 26 to approximately 80 substances. Brands selling in the EU should review their fragrance disclosure requirements against the updated allergen list.

US Requirements: 21 CFR 701.3

In the United States, cosmetic ingredient labelling is governed by 21 CFR 701.3. The key requirements:

Placement. The ingredient declaration must appear on the label of the cosmetic product. For products in containers with an outer carton, the declaration may appear on either the container or the outer carton, provided it is "conspicuous" and meets the location requirements.

Minimum type size. The ingredient list must be in type no smaller than 1/16 inch (approximately 4.5pt). This is the minimum — for readability, 6pt is the practical minimum for most substrates.

Header. The ingredient list must be preceded by the word "Ingredients:" (with the colon).

Language. INCI names are technically Latin or chemical systematic names, not English. They may appear exactly as they are in the INCI dictionary without English translation.

Water. Water (INCI: Aqua) must be declared when present, typically as the first ingredient since it is usually the primary ingredient by weight in aqueous formulations.

Professional products. Products sold only to licensed professionals and not for retail sale to consumers have different labelling requirements — the professional-use ingredient declaration can appear on a separate insert or accompanying documentation rather than on the primary label.

EU Requirements: Regulation (EC) 1223/2009

The EU Cosmetics Regulation (EC) 1223/2009 governs cosmetic labelling across the EU. Post-Brexit, the UK has retained equivalent requirements through the UK Cosmetics Regulation (retained EU law).

Placement. The ingredient list must appear on the container and any outer packaging.

Header. The list must be preceded by "Ingredients" (or the equivalent in the official language of the country of sale — "Ingrédients" in French, "Ingredienti" in Italian, etc.). Note: in the EU, the header is "Ingredients" not "Ingredients:" — no colon is required.

INCI names. EU labelling uses the same INCI names as the US, with the exception that common names may be used in addition to INCI names for clarity in some cases.

Fragrance allergens. As noted above, the 26 EU-listed fragrance allergens (extended to approximately 80 under the 2023 update) must be disclosed individually when present above threshold levels.

Nanomaterials. Any cosmetic ingredient used in nano form must be indicated in the ingredient list by the word "[nano]" following the INCI name of the nanomaterial.

Responsible Person. EU cosmetics require a designated Responsible Person (RP) established within the EU (or, post-Brexit, a separate UK Responsible Person) who has product responsibility for compliance with the Cosmetics Regulation. The RP's name and address must appear on the label.

Practical Layout Considerations for the Ingredient List

The ingredient list for a modern cosmetic formulation often contains 20–40 INCI names, some of which are long chemical strings. Fitting this on packaging is a layout challenge that must be addressed from the start.

Minimum type size decisions. The regulatory minimum in the US (1/16 inch, approximately 4.5pt) is the floor, not the recommendation. 4.5pt type is difficult to read under most lighting conditions, particularly for consumers with vision impairment. 6pt is the practical minimum; 7–8pt is preferable wherever space allows.

Container vs. outer carton. For very small containers (under 30ml) where label space is genuinely insufficient, the EU Cosmetics Regulation (and FDA practice) allows the ingredient list to appear on the outer carton rather than the primary container, provided the outer carton is present at the point of sale. This is common practice for cosmetics sold in folding carton boxes.

Abbreviated disclosure rules. For cosmetics that are too small to carry the full ingredient list (the EU defines this as surface area of 10cm2 or less), the ingredient list can be printed on a leaflet or inner card, provided the label bears a reference to it.

Language for multi-market products. Products sold across multiple EU countries may require the ingredient list in multiple languages, or may use the international INCI names (which are standardised and require no translation) with a multilingual header ("Ingredients / Ingrédients / Ingredienti / Inhaltsstoffe"). Many brands use INCI names exclusively for the ingredient list and translate only the marketing and regulatory text.

Common Errors in INCI Labelling

Using common names instead of INCI names. "Coconut oil" is not the INCI name. The INCI name is "Cocos Nucifera (Coconut) Oil." "Vitamin E" is not the INCI name; "Tocopherol" or "Tocopheryl Acetate" is.

Incorrect ingredient order. The most common error is listing ingredients alphabetically, in order of marketing importance, or in the order the formulator added them — none of which is the correct descending-by-weight order.

Missing fragrance allergen disclosure in EU products. Many brands declare only "Parfum" without checking whether any of the regulated fragrance allergens are present above threshold. Failure to disclose these allergens when they are present above threshold is a labelling violation.

Not updating the ingredient list after formulation changes. If the formulation is adjusted — a concentration change, an ingredient substitution — the ingredient list must be updated and new artwork files produced. Producing products with outdated ingredient lists is a regulatory violation and a consumer safety risk for anyone with allergies.

Missing [nano] designation. Brands using cosmetic-grade titanium dioxide or zinc oxide in nanoparticle form for SPF products must check whether the nano designation is required under EU rules.

FAQ

Where do I find the official INCI name for an ingredient? The PCPC's International Cosmetic Ingredient Dictionary and Handbook is the US reference. The EU's CosIng database (available at ec.europa.eu) is freely searchable online and includes INCI names, function descriptions, and restrictions for EU-regulated ingredients. Your formulator or contract manufacturer should supply a compliant ingredient list as part of their technical documentation.

Can my formulator write my ingredient list for me? Yes — and they should. A contract manufacturer or formulator who produces finished cosmetic products should supply a compliant INCI ingredient list as part of the product specification documentation. This list should then be reviewed by a regulatory consultant before it goes to artwork, particularly for EU or UK products where allergen disclosure, nano designation, and Responsible Person requirements add complexity.

Do I need different ingredient lists for the US and EU? The ingredient names are the same (INCI is international), but the format requirements differ — the US requires "Ingredients:" with a colon; the EU does not. The EU requires individual fragrance allergen disclosure. The EU requires nano designation. For products sold in both markets, the safest approach is to include the most demanding requirements (EU allergen disclosure, nano designation) on all versions of the label, since the US regulations do not prohibit these disclosures.