The short answer is that the ingredient list of any cosmetic — from a moisturiser to a shampoo — follows a naming system common across the whole European Union called INCI, and is ordered from the highest concentration down to 1%. Below that, the order is no longer mandatory. With that single rule you can already get a great deal out of any label, even if the names look like Latin or technical English.
What INCI is and why it’s the same across Europe
INCI stands for International Nomenclature of Cosmetic Ingredients, a standardised naming system that requires the same ingredient to be named identically on a product made in Spain and one made in France or Germany. Names are given in Latin when the ingredient is of plant or mineral origin (for example, Aloe Barbadensis Leaf Juice) and in English when it is a chemical or synthetic substance (for example, Sodium Chloride). This nomenclature is mandatory on cosmetic labelling in the EU under Regulation (EC) No 1223/2009, which governs all the information that must appear on the pack: composition, intended function of the substances, country of manufacture, quantity, minimum durability date and warnings for use.
A name being in Latin or English does not mean the ingredient is exotic or dangerous: water is declared as Aqua, and it is usually the first ingredient on the list in creams, gels and shampoos because it is the majority component.
How the list is ordered: the 1% rule
This is the practical key to the whole system:
- Ingredients at a concentration above 1% must appear in descending order, from the largest amount to the smallest.
- Ingredients at a concentration of 1% or less may appear in any order, normally at the end of the list.
- Colourants (identified by the prefix “CI” followed by a number, such as CI 77891) may be listed in any position, regardless of their concentration.
In practice, this means the first five to eight ingredients set the base and texture of the product (water, emollients, surfactants), and that from halfway down the list you can no longer deduce quantities precisely. An active can sit in fifteenth place and be effective at a low concentration; its position alone does not tell you whether the product “works”.
Ingredients worth being able to spot
| INCI term | What it is | Where it usually appears |
|---|---|---|
| Aqua / Water | Water, the base solvent | Almost always the first ingredient in creams and gels |
| Parfum / Fragrance | A mixture of aromatic substances | Perfumed creams, gels and shampoos |
| Alcohol / Alcohol Denat. | Ethyl alcohol, used as a solvent or for a light feel | Gels, toners, deodorants |
| Parabens (e.g. Methylparaben) | Preservatives preventing bacterial and fungal growth | Products with a water phase (creams, lotions) |
| CI + number | An authorised colourant, identified by its colour index code | Make-up, coloured products |
| Names ending in “-oxynol” or similar | Surfactants or emulsifiers | Cleansers, shampoos |
Seeing “Parfum” or “Fragrance” on the list does not tell you which specific aromatic substances the product contains, unless one of them is a mandatory-declaration allergen, which must be named individually once it passes a given threshold. This matters particularly if you have sensitive skin or a history of contact dermatitis.
Fragrance allergens: what changed in August 2026
This is a point that has changed recently and is worth knowing. Until now, European rules required 24 fragrance allergens to be declared individually when they exceeded certain concentration levels. From 1 August 2026, Regulation (EU) 2023/1545 extends that list to 81 substances, which must appear under their INCI name within the ingredient list when their concentration exceeds 0.001% in leave-on products (a day cream, for instance) or 0.01% in rinse-off products (a shampoo or shower gel).
According to the Spanish Agency of Medicines and Medical Devices (AEMPS), this extension does not mean cosmetics are less safe: fragrance allergens are safe substances for most people and only cause a reaction in those already sensitised to them. The aim of the change is to let those people identify more easily, by reading the label, the products they need to avoid. Products already on the market before 31 July 2026 may continue to be sold with the old labelling until 31 July 2028, so for a while packs carrying different allergen information will sit side by side on the shelves.
If you have ever reacted to a perfume or a scented cream, it’s worth asking your pharmacist or dermatologist for the full list of declarable allergens and comparing it against the INCI of the product you want to buy.
The PAO symbol: the open jar with a number
Besides the minimum durability date (the hourglass symbol or a specific date), many cosmetics carry a drawing of an open jar with a number followed by the letter “M”, for example “12M” or “24M”. This is the PAO symbol (Period After Opening) and it indicates how many months you can go on using the product safely once opened, provided you store it in normal conditions. This symbol is only mandatory when the product has a shelf life longer than 30 months; if it is shorter, the manufacturer must give a specific expiry date instead.
Once a cosmetic is opened, factors such as air getting in, light, or repeated contact with fingers accelerate the deterioration of the product and its preservatives, so the PAO is a useful reference beyond the date printed on the box.
How to read a label in practice
- Look at the front first: product name, function and net volume or weight.
- Find the PAO symbol or the minimum durability date to know how long you can use it.
- Run through the first few INCI ingredients to understand the base of the product (water-based, oil-based, with or without alcohol).
- If you have sensitive skin or known allergies, look specifically for “Parfum”, “Fragrance” and the allergen names you already know from previous experience.
- Check the country or the EU as the manufacturing area, and the details of the responsible person, both mandatory on every cosmetic marketed in Europe.
When to seek advice
Ask your pharmacist, or see a dermatologist, if:
- You notice itching, redness, swelling or blistering after using a new cosmetic, particularly if it coincides with a perfumed ingredient.
- You have a history of contact dermatitis and want to identify which specific substance triggers it before trying a new product.
- The reaction affects a large area of skin, doesn’t improve within a few days of stopping the product, or is accompanied by difficulty breathing or facial swelling: in that case, seek urgent medical attention.
- You are unsure whether a specific ingredient is compatible with a dermatological treatment you are already on.
This article is for information only and does not replace assessment by a healthcare professional. Sources: AEMPS – New fragrance allergens to be labelled in cosmetics, Regulation (EC) No 1223/2009 on cosmetic products (EUR-Lex), Regulation (EU) 2023/1545 on fragrance allergen labelling (EUR-Lex).