The words an ingredient list is not allowed to use

The usual complaint about an ingredient list is that it is deliberately impenetrable. It is impenetrable, but the brand mostly did not choose that. Article 19 of the EU Cosmetics Regulation requires every ingredient to be printed under the common ingredient name set out in the glossary kept under Article 33 of the same regulation. That glossary is a real document with more than five thousand entries, built on the International Nomenclature of Cosmetic Ingredients, and for anything that grew in the ground the entry is a Latin binomial: ABIES ALBA LEAF OIL, ACHILLEA MILLEFOLIUM EXTRACT.

So the front of the box and the back of the box are written in two different languages by design. The front may say what it likes, within the claims rules. The back must say Houttuynia Cordata Extract, because that is the name in the glossary, and “heartleaf” is not.

Nothing stops a brand from adding the English in brackets. The glossary name has to be there; a translation alongside it is allowed and costs a few millimetres of print. Almost nobody bothers.

of 5,941 printed entries give a second, readable name

7%of 5,941 printed entries give a second, readable namee.g. Butyrospermum Parkii (Shea) Butter

of the 274 botanical entries do

17%of the 274 botanical entries dofive in six plants are Latin only

ingredients we document are printed under more than one name

54 of 280ingredients we document are printed under more than one nameacross masks on the same shelf

Start with the ingredient every mask contains. Across 215 masks, the entry for water is printed 14 materially different ways, not counting capitalisation, which varies too. Aqua on 94 packs, Water on 53, Aqua (Water), Aqua / Water / Eau, Water(Aqua), Purified Water. All the same ingredient, all lawful, and a shopper comparing two labels letter by letter has no way to know that.

It is not only water. Of the 280 ingredients this site documents and can match to a printed entry, 54 appear under two or more different names depending on the pack. The pattern that matters is the optional translation, because it is the one that decides whether you can read the label at all:

The last row is the harder version. Those three names are not translations of centella; they are the compounds a centella extract is standardised for, declared separately. A reader hunting for the word on a cica mask can find nothing that looks like it and still be holding three centella-derived ingredients.

76 of the 215 masks here put an ingredient into their own product name. That word is a promise a shopper can, in principle, check against the list. In practice the check fails for a reason that has nothing to do with Latin: the front of the box names a substance in general, and the glossary names one specific molecule.

6 masks here are named after vitamin C. Between them they declare 4 different ingredients, and only one of the 6 prints Ascorbic Acid, the molecule vitamin C actually is, and it sits in last place, entry 33 of 33, on TONYMOLY Master Lab Sheet Mask Vitamin C.

Balea

3-O-Ethyl Ascorbic Acid, #7

Garnier

Ascorbyl Glucoside, #5

Schaebens

Sodium Ascorbyl Phosphate, #9

None of that is a trick. Ascorbic acid is famously unstable in water, so formulators reach for derivatives, and a derivative is a genuinely different ingredient with its own glossary entry, which is precisely why the label may not call it “vitamin C”. The consequence is narrower than a scandal and more useful: the front tells you which family was chosen, only the back tells you which member, and those are different questions.

The regulation makes the same distinction, in reverse

Retinol is the clearest case, because here the EU has done the arithmetic out loud. 5 masks here are named after retinol; the entries they actually print are Retinyl Palmitate, Retinyl Acetate and, once, Retinol (10 ppb). Since 2024, Retinol, Retinyl Palmitate and retinyl acetate share a single Annex III entry with one ceiling: 0.3% for a rinse-off or leave-on product, counted as Retinol Equivalent, the three added together and converted to the retinol they amount to.

Of the 13 front-of-box words we tested, 6 are printed on the back, at least sometimes, under a name that contains no trace of the word itself. This is the translation table the box does not print:

Nothing in the regulation asks a brand to print how much of an ingredient is in the pack. Concentrations live in the product information file held by the responsible person; the label gets an order, not a recipe. Which is what makes the exceptions worth reading: across 5,941 printed entries, 17 carry a number the brand volunteered.

They run further than you would expect in both directions. The largest is Centella Asiatica Extract (51%) on SKIN1004 Madagascar Centella Watergel Sheet Ampoule Mask, first on its list: a brand using the number as the claim. The smallest is on a mask named after the ingredient in question:

Ten parts per billion is 0.000001%, three hundred thousand times below the ceiling the EU sets for retinol in a product like this. Whether the intended figure was parts per billion or parts per million, the label is the only document a shopper can read, and this is what it says.

Read the entry beside it, though, and the asymmetry is the lesson. The neighbouring name is Retinal, retinaldehyde, a different and more active vitamin A form, printed with no number at all. The one figure this pack volunteers is for the ingredient in its own title; the one that may be doing the work arrives undeclared, like every other entry on every other list.

The same brand’s AHA-BHA-PHA mask does it three times over: Citric Acid(1 Ppm), Salicylic Acid(1 Ppm), Lactobionic Acid(1 Ppm) : the three acids the product is named for, each at one part per million.

Across the 76 masks that name an ingredient, almost all of them declare something from the family they invoke, somewhere on the list. Three do not, and the clearest of the three is instructive because the same brand gets it right on the next product along.

Abib Collagen Gel Mask Heartleaf Jelly is sold as a heartleaf mask. Heartleaf is Houttuynia Cordata Extract, and no form of it appears in the 43 entries the pack prints. What the list does contain is collagen extract, second from last, and rose of Jericho. Meanwhile Abib Gummy Sheet Mask Heartleaf Sticker, same brand and same word on the front, declares Houttuynia Cordata Extract at position 5 of 29, high on the list, where a hero ingredient would be expected to sit.

Under the EU claims criteria this is the one situation with a bright line: if a product claims to contain a specific ingredient, that ingredient shall be deliberately present, and a claim that borrows an ingredient’s properties has to be supported, “such as by demonstrating the presence of the ingredient at an effective concentration”. A name is a claim. An ingredient list that does not contain it cannot support one.

None of this needs chemistry. It needs about eight pairs of words, after which most front-of-box claims become checkable in the shop:

• Vitamin C is ascorbic acid; on the back expect Sodium Ascorbyl Phosphate, ascorbyl glucoside or 3-O-ethyl ascorbic acid.
• Retinol and pro-retinol are Retinyl Palmitateor retinyl acetate, counted against retinol’s limit as retinol equivalent.
• Vitamin E is Tocopherol or Tocopheryl Acetate.
• Collagen is Collagen Extract, Hydrolyzed Collagen or soluble collagen.
• Hyaluronic acid is usually Sodium Hyaluronate, its salt.
• Green tea is Camellia Sinensis (Green Tea) Leaf Extract, and check the plant part, because a seed extract is not the leaf.
• Heartleaf is Houttuynia Cordata Extract; mugwort is artemisia; cica is Centella Asiatica Extract and its asiaticosides.

Then two habits. Look for the ingredient the front names and note where it sits rather than only whether it is there; the ≈1% line is what turns a position into a rough dose. And when a pack prints a number, believe the number. Every decoded panel on this site does both jobs at once, carrying the entry as printed beside the encyclopaedia entry it matches, and saying so plainly where there is no entry yet.