A soap maker's intro to INCI labels

INCI is the naming system cosmetic labels use: one standard name per ingredient, so a label reads the same in Helsinki and in Lisbon. Olive oil becomes Olea Europaea Fruit Oil. Lye is Sodium Hydroxide. Water is Aqua. Your soap already contains these, the label just needs to say so in the shared language.

This guide describes the EU rules, since that is where most of our makers sell. The logic is similar elsewhere, the details are not, so check your own market before printing.

Two accepted ways to list a soap

Cold process soap is chemically a new thing: oils plus lye become soap plus glycerin. The EU accepts two styles of declaring that:

• As weighed: list what went into the pot: Olea Europaea Fruit Oil, Aqua, Sodium Hydroxide, and so on.
• As reacted: list the saponified result: Sodium Olivate, Glycerin, Aqua.

Both are fine. Pick one style and keep it consistent across your products, mixing the two on one label is where confusion starts.

Order by weight

Ingredients are listed in descending order by weight at the time they went in. Everything at 1% or more must be in order; ingredients below 1% may follow in any order after them. In practice that means your main oils lead the list, and the essential oil that makes up 2% of the batch sits near the end.

Allergens get their own line

Certain fragrance components, many of them natural parts of essential oils, must be named individually when they exceed 0.01% in a rinse-off product like soap (0.001% in leave-on products).

A worked example: your recipe uses 3% lavender essential oil, and lavender oil typically contains around 25 to 35% linalool. That puts roughly 0.9% linalool in the finished bar, well above the 0.01% threshold, so Linalool appears on the label as its own entry. The same maths usually adds Limonene and Geraniol for citrus and floral oils. Your essential oil supplier's allergen declaration gives you the percentages to calculate from.

The rest of the label

• Net weight in grams.
• Batch or lot number, so a bar can be traced back to its production run.
• Responsible person: a name and EU address that answers for the product.
• Durability: a best before date if under 30 months, otherwise a period after opening symbol. Most bar soaps take the 30 month route.
• Country requirements such as language: in Finland, the mandatory particulars need to be in Finnish and Swedish.

One honest caveat to close on: in the EU, handmade soap is a cosmetic, and the label is only one part of placing a cosmetic on the market. A safety assessment, a product information file and a CPNP notification come with it. That is beyond this guide, but it should be on your map.