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Melt-and-pour and liquid soap labels: what to list

Published 22 September 2026; rules last checked 25 September 2026. A labelling reference, not legal advice.

The label carries every ingredient of the base, in the supplier's order, plus everything you added, each in its weight position. Article 19(1)(g) defines an ingredient as "any substance or mixture intentionally used in the cosmetic product during the process of manufacturing", so a melt-and-pour base is not one ingredient but a list of them, and the supplier's INCI list for the base is the starting point. Fragrance goes in as "Parfum" with its declarable allergens, colour goes last by its CI number, and a liquid soap made with potassium hydroxide uses the potassium salt names.

Melt-and-pour: the base is a list, not a line

A melt-and-pour base is a finished mixture, and the only person who knows what is in it is the supplier. Their specification sheet carries the INCI list in descending order of weight. Copy it; do not paraphrase it, and do not shorten it. Then add what you put in:

• Fragrance as "Parfum", in its weight position, followed by each declarable allergen the oil brings over 0,01 % of the finished soap. The method is on the fragrance page.
• Colour by its CI number where one exists (Article 19(1)(g): colorants "may be listed in any order after the other cosmetic ingredients", using "the CI (Colour Index) nomenclature ... where applicable"). Micas and pigments usually carry a CI number on the supplier's sheet.
• Botanicals, clays, exfoliants by their glossary names, at their weight positions.

Order is by weight "at the time they are added". The base's ingredients were added as part of the base, so their proportions are the base's proportions scaled to the base's share of your batch. Ingredients under 1 % of the finished product may be listed in any order after those over 1 %, which is what makes this workable without a full breakdown of the base: ask the supplier for the percentages of their ingredients above 1 %, slot each of your additions into weight order among them, and let the sub-1 % tail sit in any order.

Liquid soap: the potassium names

A liquid soap is saponified with potassium hydroxide instead of sodium hydroxide, and the salts have their own glossary names: "Potassium Olivate" (entry 22715), "Potassium Cocoate" (22594) and their siblings. Water is usually the largest ingredient by weight in a liquid soap, so "Aqua" (2112) commonly comes first, then the potassium salts in descending order, then "Glycerin" (11096), then fragrance and its allergens, then anything under 1 %. That is the as-made reading; the as-added reading lists the oils by their botanical names, "Aqua" and "Potassium Hydroxide" (22655). Both are explained on the sodium-hydroxide page, and either way the alkali is accounted for. Our soap tool reads a "Potassium hydroxide" line and prints the potassium salts, but only for oils whose potassium salt has a name in the glossary: olive, coconut, castor, palm, palm kernel, shea, sunflower (high-oleic too), rapeseed and canola, tallow, babassu, safflower and soybean. Sweet almond, cocoa butter, avocado, grapeseed, lard, mango butter and argan have no such name in the glossary or in CosIng, so a recipe containing one of them is printed whole in the as-added form, oils by botanical name with "Potassium Hydroxide", and the note says why. Jojoba and beeswax keep their own names in both forms, and the fragrance and allergen arithmetic is the same in both.

Shower gels and surfactant products

A "liquid soap" made from purchased surfactants rather than saponified oils is a rinse-off cosmetic, not a soap in the chemical sense, and the same rule as melt-and-pour applies: each surfactant, the water, the thickener and the preservative by their INCI names from the suppliers' sheets, in weight order. Our soap tool accepts supplier INCI names for ingredients it does not resolve itself, prints them exactly as entered, and flags a supplier line that carries several names, because strictly each of those components belongs at its own weight position.

Elsewhere

• Great Britain. Article 19 of the assimilated regulation is the same text: the same definition of ingredient, the same order, the same CI rule. The names are the same, under other entry numbers in the glossary Great Britain kept from the EU; Potassium Shea Butterate is newer than that glossary and is used there as the generally accepted nomenclature that Article 19(6) points to.
• United States. A melt-and-pour bar that meets the soap definition in 21 CFR 701.20 and is sold only as soap needs no ingredient list; one sold as a cosmetic lists its ingredients in descending order of predominance under 21 CFR 701.3.

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