Allergen threshold calculator

The sum, in words

A declarable fragrance allergen has to be named in the ingredient list when it exceeds 0.001 percent of a leave-on product, or 0.01 percent of a rinse-off one. Both figures are percentages of the finished product as sold. Your concentrate is diluted into that finished product, so multiply the allergen's share of the concentrate by the concentrate's share of the bottle, and divide by a hundred.

A material at 0.006 percent of your concentrate, in an eau de parfum at 20 percent, arrives at 0.006 multiplied by 20, divided by 100, which is 0.0012 percent of the finished product. That is over 0.001 percent, so for a leave-on product it goes on the label.

The same material at 0.004 percent of the concentrate arrives at 0.0008 percent, which is under, and does not.

It goes wrong in both directions

Screen your concentrate directly against 0.001 percent and you over-declare by the whole factor of the dilution: a longer label, a more alarming one, and a statement about your product that is not true.

Take a concentrate assessed for a 20 percent eau de parfum and bottle it neat as a perfume oil, and every figure is five times larger. Materials that were under are now over, and the label is short by however many of them crossed. The declaration is a consequence of the formula and the strength together, so it is not a property of the concentrate at all.

Which list, and which market

Regulation (EU) 2023/1545 rewrote and lengthened the European Union list. The first deadline passed on 31 July 2026, so anything entering the EU market now must carry the expanded list; stock already on the market has until 31 July 2028.

Canada uses the same thresholds and has aligned to the same list on almost the same timetable. Great Britain did not adopt the expansion and retains the shorter pre-2023 list, so a label built for one is not automatically right for the other. The thresholds themselves did not diverge.

What this calculator does not do

It works out one contribution from one route. Three things decide a real declaration and none of them is in this sum.

• An allergen usually arrives by more than one route: as a line of its own, and inside the naturals on the formula. Lavender oil carries linalool, and that linalool counts.
• Some entries are grouped and are summed before they are judged. Citral covers citral, geranial and neral together, and three figures each under the threshold can be one figure over it.
• Bench dilutions carry solvent that is not material, so what you weighed and what you dosed are different numbers.

So treat an answer here as one line of the arithmetic rather than as a declaration. Whether it is safe to sell a particular product is a question for a qualified safety assessor.