In short
To calculate fragrance allergen declarations, work out the level of each listed substance in the finished product, adding all contributions, and compare with the threshold for that product type and market. In the EU that's 0.001% in leave-on and 0.01% in rinse-off products. The list grew by 56 substances under Regulation (EU) 2023/1545, with new products required to comply from July 31, 2026 and existing products by July 31, 2028. This lesson works through the calculation, which is the same in other markets only where their rules say so. Canada's rules are similar in thresholds, for example, while the US FDA's rule has not been finalized at our last check.
What you will learn
- Calculate finished-product allergen levels
- Apply leave-on and rinse-off thresholds
- Handle grouped entries, data gaps and reformulation
Before this lesson: Constituents of Naturals in Restriction Checks
The calculation
% in product = Σ (share of line in concentrate × % allergen in line) × concentrate in product
Worked example, with invented compositions. An eau de parfum at 15% concentrate.
| Line | Share of concentrate | Linalool in line | In concentrate |
|---|---|---|---|
| Lavender oil | 5.0% | 30% | 1.50% |
| Bergamot oil | 8.0% | 10% | 0.80% |
| Linalool | 2.0% | 100% | 2.00% |
| Purchased accord | 10.0% | 5% (statement) | 0.50% |
| Total | 4.80% |
In the product: 4.80% × 0.15 = 0.72%, which is far above 0.001%. So it's declared. For most natural-rich fragrances the question isn't whether a common allergen appears, but how many.
How small the threshold is
For a leave-on perfume at 15% concentrate, 0.001% in the product equals about 0.0067% in the concentrate, or 67 mg per kg of concentrate. A trace of a material at 0.1% in the concentrate carrying 10% of an allergen gives 0.01% in the concentrate, which is 0.0015% in the product, above the threshold. That's why trace lines matter here, and why you need good data. It's also why a "not detected" result depends on the method's limit.
Practical complications
| Issue | What to do |
|---|---|
| Grouped entries in the regulation | Read how the entry is written, including what counts within it. Citral is one example noted in our reference log. |
| New natural-extract entries | Some listed items are extracts. Check whether your material matches the listed name and species. |
| Purchased compounds | Ask for an allergen statement that covers the 2023/1545 list, with date and version. |
| Old statements | A statement covering only the original 26 substances doesn't answer the expanded list. |
| Lot variation | Use maximums from a grade statement, or lot data if you have it. |
| Solvents, carriers, other sources | A cosmetic's other ingredients may also contain listed substances. Ask the formulator. |
| Naming | Use the name the regulation requires. See ingredient labeling. |
Thresholds, restrictions and safety
Keep three questions separate. A labeling threshold decides whether a name appears. A restriction decides whether the level is permitted. A safety assessment decides whether the product is safe for its use. A substance under the threshold may still matter to a sensitized person. And "allergen-free" is a claim that needs evidence, and possibly doesn't tell the whole story.
Reducing declarations
Some brands choose to cut the list. Take care: a long list is often normal, and many declarable substances are ordinary, useful materials. Removing them can change odor, and replacements bring their own constituents. The guide on reducing declarable allergens sets out the method. Treat any change as a reformulation, with a blind test and full rechecks.
Practical exercise: An allergen worksheet for one product
Practice first, using invented data. A body lotion, leave-on, has 1.0% fragrance. The fragrance holds 0.5% of allergen P and 0.05% of allergen Q. A shampoo, rinse-off, has 1.0% of the same fragrance.
- Calculate P and Q in each product. (Lotion: 0.005% and 0.0005%. Shampoo: the same figures.)
- Decide which to declare under the EU thresholds. (Lotion: P only. Shampoo: neither, since both are below 0.01%.)
- Now take your own formula, and choose a product and market. Find the current list, and record the date.
- Ask suppliers for statements for each natural and compound, and record which list each covers.
- Build a worksheet with contributions and thresholds, and write a provisional declaration list.
- Write an action for each gap, marking what a qualified person must confirm.
You have done this well if your practice answers match, your worksheet adds contributions correctly, and missing data is flagged rather than left out.
Common mistakes
- Using the concentrate figure against the threshold. Use the product figure.
- Relying on an old 26-allergen statement. The list has changed.
- Confusing labeling with a safe limit. They answer different questions.
Knowledge check
Written and reviewed by the RUŌOD Lab team. This is general education, not legal, regulatory, medical or safety advice. Example dilutions and exercises are for learning, are not validated products, and have not been safety-assessed. Completing a lesson confers no qualification. How we check these lessons.