Why Are Cosmetic Ingredient Names Written in Katakana? | The Relationship Between Labeling Names and INCI Names

On the back of a cosmetics box, you will see ingredient names written in katakana or abbreviations, such as “Dimethicone,” “Tocopherol,” and “BG.” These are not names translated independently by each company; they are written according to common “labeling names” prepared by an industry association. In this installment of “Labeling Rules,” we will organize where those names come from.

Full ingredient labeling and the “List of Cosmetic Ingredient Labeling Names”

In Japan, since April 2001, cosmetics have been required to display all ingredients used in the product, known as “full ingredient labeling.” If the same ingredient were written under different names by different companies, it would be impossible to compare products, so the Japan Cosmetic Industry Association, formerly the Japan Cosmetic Industry Association Federation, created the “List of Cosmetic Ingredient Labeling Names.” In the association’s explanation of its purpose, it states that when displaying all cosmetic ingredients under the Act on Securing Quality, Efficacy and Safety of Products Including Pharmaceuticals and Medical Devices, the names in this list are to be used.

For each ingredient, the list includes the labeling name, INCI name, definition, and ingredient number as a set. According to the association’s website, the name list contains 16,908 ingredients from No.1 to No.49 as of September 2026. For new raw materials that are not on the list, a labeling name can be created by applying to the association. The association also explains that inclusion of a name in the list does not relate to the safety of the ingredient.

The INCI names behind the katakana

INCI names, or the International Nomenclature of Cosmetic Ingredients, are international labeling names for cosmetic ingredients created by the U.S. industry association Personal Care Products Council (PCPC). From the perspective of international alignment, or global harmonization, the Japan Cosmetic Industry Association creates labeling names based on INCI names, and in 2002 it established “Guidelines for Creating Labeling Names.” Because names of chemical substances and similar terms are often transferred into Japanese based on their English sounds, katakana stands out in ingredient labeling. At the same time, some names are translated into Japanese, as in the case of Water being displayed as “water.”

Ingredient names written in katakana become easier to read if you think of them as “INCI names, which are international names, transferred into Japanese notation.” Because the name list records labeling names together with their corresponding INCI names, it can also serve as a clue when comparing English ingredient labels on overseas products.

INCI is also the basis in the EU

Article 33 of the EU Cosmetics Regulation, Regulation (EC) No 1223/2009, provides that the European Commission shall compile and update a glossary of common ingredient names, taking into account internationally recognized nomenclatures including INCI. Ingredient labeling uses these common ingredient names. Even if the language of notation differs by country or region, aligning the underlying names makes it possible to identify the same ingredient as the same ingredient.

How to read the order in which ingredients are listed, and how ingredients used in small amounts are handled, is How to Read the Full Ingredient List explained in detail here.

References: Japan Cosmetic Industry Association; European Commission (Official Journal of the European Union, Regulation (EC) No 1223/2009)

—The Value Village Editorial Team