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Articles·Beautician·Materials and chemistry

Product chemistry and INCI declaration

How to read a product declaration and understand active substances

As a beautician you work daily with products covered by common EU rules. The Cosmetics Regulation (EC) no. 1223/2009 sets out the main requirements for safety and labelling of cosmetic products throughout the EU and the Danish cosmetics order supplements with rules on supervision and requirements for the required marking to be in Danish. Being able to read and understand a declaration is therefore a professionally crucial competence — not just a formality.

§What is on a declaration?

The ingredients in a cosmetic product must be stated with their INCI name – International Nomenclature of Cosmetic Ingredients, the common international naming system for cosmetic ingredients. Ingredients are listed in descending order by amount, so the first names on the list make up the most of the product.

  • 01Aqua — water, often the most widely used ingredient
  • 02Glycerin — a humectant used widely in skincare
  • 03Perfume — umbrella term for fragrances, a known source of allergic reactions
  • 04Alcohol denat. – denatured alcohol, can have a drying effect at high concentrations

§pH and active ingredients

Beyond the ingredient list, the product's pH value is important because it affects how the product works together with the skin's own, slightly acidic acid mantle. Many modern products contain active ingredients that can give good results but also require that you know their effect and risk of irritation.

Ingredient typeExampleBe aware of
Acids (AHA/BHA)Glycolic acid, salicylic acidCan cause irritation and increased sun sensitivity
A-vitamin derivativesRetinolCan cause redness and scaling at high concentration or too frequent use
Moisture-binding substancesHyaluronic acidGenerally suitable for most skin types, but quality and concentration vary

§Your responsibility as a professional

One of the professional objectives of the education is precisely to be able to communicate about and perform treatments with products according to the manufacturer's manuals and use protective equipment where required. This means you must be able to explain to a customer what is in a product, why you choose it and when a product is not suitable at all — for example due to known allergy to a specific ingredient.

The good beautician knows not only the effect of a product — but also its contents.