What Are Label Allergens, and Why Shorten the List?
That long Latin tail on the back of a perfume bottle is no accident. Cosmetic regulations require that certain fragrance materials be declared individually on the label by their INCI name whenever their concentration in the finished product exceeds a defined threshold. Shortening that list is not a cosmetic trick — it means redesigning the architecture of your formula from the ground up.
Turkey's Cosmetics Regulation runs in parallel with EU Regulation 1223/2009. Within this framework, 26 mandatorily declared fragrance allergens were discussed for many years. Under the new rules, that list has been expanded to approximately 80 substances, with a transition period granted to manufacturers. For the current transition schedule and the up-to-date list, always refer to the applicable regulatory text and TİTCK announcements; the figures in this article are for guidance only and do not constitute legal text.
Declaration thresholds fall into two categories:
| Product type | Example | Declaration threshold (in finished product) |
|---|---|---|
| Leave-on | Perfume, body spray, cream, deodorant | 0.001% (10 ppm) |
| Rinse-off | Shampoo, shower gel, liquid soap | 0.01% (100 ppm) |
Note: Perfume is a leave-on product. That means the strictest threshold applies to you. 0.001% equates to 10 milligrams per kilogram of finished perfume. Once you truly absorb that number, you will understand why "shortening the allergen list" is solved through substitution, not dilution.
"Allergen-free perfume" does not exist. You can build a formula that contains no mandatorily declared allergens — but no molecule can guarantee it will never cause a reaction in anyone. In labelling and marketing copy, use "contains no mandatorily declared fragrance allergens" or "low-allergen profile" rather than "allergen-free". The first is a claim; the second is a declaration — the difference becomes apparent under regulatory scrutiny.
Let us also dispel a common misconception: natural does not mean safer. A significant proportion of the substances on the declaration list — Citral, Eugenol, Isoeugenol, Geraniol, Limonene, Linalool, oakmoss constituents — occur most abundantly in nature within essential oils. Natural bergamot is phototoxic due to its furanocoumarins and can cause permanent pigmentation marks on skin exposed to sunlight. By contrast, certain pure synthetics such as Ambroxan and Iso E Super do not appear on the allergen declaration list. Safety depends not on the source of a raw material but on the molecule and the level at which it is used.
Threshold Maths: A Simple Two-Factor Gate
Allergen calculation in formulation comes down to a single multiplication. Yet hundreds of manufacturers who get that multiplication wrong end up returning to the drawing board after their labels have already been printed.
The formula is:
Allergen level in finished product = (Allergen level in fragrance oil) × (Fragrance oil level in formula)
Example: Your supplier's declaration for a fragrance oil states 10% Linalool. You are using that fragrance oil at 15% in your formula. Result: 0.10 × 0.15 = 1.5%. Since the threshold is 0.001%, you are at 1,500 times the declaration limit. Linalool will appear on the label. No argument.
Now let us look at it in reverse. How low must the allergen level in the concentrate be for it to remain invisible on the label?
| Fragrance oil level in finished product | Product type | Max. allergen permitted in concentrate (leave-on, 0.001% target) |
|---|---|---|
| 25% | Extrait concentration | 0.004% |
| 20% | EDP range | 0.005% |
| 15% | EDP / heavy EDT | 0.0067% |
| 10% | EDT range | 0.010% |
| 5% | Cologne / EDC | 0.020% |
| 1% | Body spray, baby/children's segment | 0.100% |
The table's lesson is clear: dilution will not save you. Dropping from 25% to 10% increases the permitted allergen headroom by only two-and-a-half times. Yet a typical lavender oil contains linalool at 25–45%. Even if you used that oil at just 0.01% — a level at which the scent would barely be perceptible — you would still be pushing the threshold. It is mathematically impossible to escape declaration by simply using less of a natural raw material.
The only realistic path is to remove that molecule from the formula and replace it with something that fulfils its olfactory role but does not appear on the declaration list.
Tip — grams or millilitres? All allergen calculations are performed by weight (g), not by volume. The specific gravity of fragrance oils varies considerably: citrus terpenes sit around ~0.84 g/ml, while heavy resins and certain synthetics can exceed 1.10 g/ml. If you try to fill a 100 ml bottle with "100 g" of formula, you will end up with overflow or underfill. Write your formula in grams, and calculate filling volume separately using volume = weight ÷ density.
One more point: IFRA limits and allergen declaration are not the same thing. IFRA sets the maximum permitted use level for individual materials by product category — it is a safety matter. Allergen declaration is the obligation to state something on the label — it is a transparency matter. A material can be well within its IFRA limit and still exceed a declaration threshold. Request both documents from your supplier separately: an IFRA compliance statement and an allergen declaration.
Allergen Load Map for Natural Oils
When examining your palette, you need to learn to look not through the lens of "this oil smells beautiful" but of "how many lines will this oil add to my label?" The map below shows which classics come at the highest cost.
| Natural raw material | Dominant declared allergens (typical range) | Label cost | Note |
|---|---|---|---|
| Clove bud oil | Eugenol 70–85%, Isoeugenol trace | Very high | Isoeugenol is also under strict IFRA restriction |
| Litsea cubeba / May chang | Citral (geranial+neral) 60–75% | Very high | Citral has a low IFRA ceiling |
| Oakmoss | Atranol / chloroatranol derivatives | Critical | Only purified grades, at very low levels |
| Lavender oil | Linalool 25–45%, Limonene, Geraniol trace | High | Adds 2–3 lines to the label on its own |
| Bergamot (natural, FC-containing) | Limonene 30–45%, Linalool, Linalyl acetate | High | Also phototoxic; FCF grade preferred |
| Ylang ylang | Benzyl benzoate, Benzyl salicylate, Isoeugenol, Linalool | High | 4+ declaration entries from a single oil |
| Rose oil / absolute | Geraniol, Citronellol, Linalool, Eugenol trace | High | Expensive raw material, expensive label |
| Cedarwood (Virginia/Atlas) | Virtually no declaration entries in practice | Low | A safe foundation for woody structures |
| Vetiver | Virtually no declaration entries in practice | Low | Earthy depth, excellent longevity |
| Frankincense / olibanum | Limonene (variable by batch) | Medium | Request batch-specific analysis |
The figures in the table are typical ranges; they shift with harvest year, distillation method, and origin. Never prepare a declaration based on general tables alone — use the analysis certificate for the specific batch you are working with.
The map tells us this: the woody, earthy, balsamic, and musk families form the natural backbone of a low-allergen formula. Floral and citrus materials are the primary sources that inflate the declaration list. When designing a low-allergen fragrance, the question is therefore not "should I drop all naturals?" but rather: which naturals do I keep, and for which purpose?
A common mistake: "I'll use terpeneless citrus and the Limonene problem disappears." Terpen removal significantly reduces the Limonene content but does not bring it to zero; and in the remaining fraction, Citral and Linalool may become more concentrated. Terpeneless grades offer a major advantage in terms of solubility and clarity — which is also connected to the haze issues seen in high-concentration products — but they do not resolve allergen declaration on their own. You still need to consult the analysis certificate.
Substitution Strategy and Building the Formula
Removing an allergen is the easy part; filling the olfactory gap it leaves behind is the hard part. That is where the real work begins. When you remove a molecule, you must replace not only its scent but its role in the formula: was it providing volume, brightness, or acting as a bridge?
Functional equivalents for common allergens can be approached as follows:
| Allergen / source removed | Its role in the formula | Non-declared substitution direction |
|---|---|---|
| Linalool (lavender, bergamot) | Soft, soapy floral volume | Dihydro-type softening molecules, clean musk base, lightly aldehydic opening |
| Limonene (citrus) | Bright, fresh opening | Aldehyde and ester combinations, very low doses of terpeneless fractions, "fresh" synthetic accords |
| Citral (litsea, may chang) | Sharp lemon brightness | Fresh molecules not derived from Citral; build the lemon effect with an ester + aldehyde balance |
| Eugenol (clove) | Spicy warmth | Woody-spicy synthetic accords, sweet-warm molecules outside the tonka/coumarin family |
| Coumarin (tonka) | Sweet, powdery base bridge | Vanillin derivatives, musk + woody base combination |
| Oakmoss | Chypre depth, dry moss | Vetiver + patchouli fractions + modern moss-substitute synthetics |
| Benzyl salicylate / benzoate (ylang, balsam) | Fixation, floral fullness | Macrocyclic and polycyclic musk combinations |
A critical point to bear in mind: backbone molecules such as Ambroxan and Iso E Super do not appear on the declaration list, and both deliver volume and longevity. This is why low-allergen formulas naturally gravitate towards an amber-woody-musk axis. Treat this not as a limitation but as a signature: a minimal, clean, skin-close scent language is already one of the most in-demand positions in the market today.
- Write the objective first, then open the formula
Decide upfront: "zero declaration entries" or "no more than two entries"? Zero is the logical target for baby/children's and sensitive-skin segments; two to three entries is acceptable for niche adult fragrance. Do not select raw materials until you have written down your target.
- Collect documentation for every raw material
For each ingredient, file the IFRA compliance statement, the allergen declaration, and the SDS (safety data sheet). Never add an undocumented raw material to a low-allergen formula; having it tested after the fact costs more than substituting it from the start.
- Build the spreadsheet and do the multiplication
Multiply the allergen percentage in each raw material by its weight fraction in the formula. The same allergen can come from multiple raw materials — Linalool from three different oils can accumulate and breach the threshold. Sum by allergen, not by raw material. This is the single most common calculation error.
- Replace high-load entries according to their function
For every allergen that exceeds the threshold, ask the "role" question as shown in the table. Do not look for a direct one-to-one replacement; it is more realistic to fill the gap by building an accord from two or three molecules.
- Rest the concentrate, then blend with alcohol
Allow the concentrate to stand on its own for 24–48 hours to let the scent balance settle. Then combine it with perfumer's alcohol (high-strength, denatured ethanol). Alcohol and solvents are highly flammable; work in a well-ventilated area, away from static electricity sources, wearing gloves and eye protection.
- Maceration at room temperature
Rest the blend in the dark at approximately 15–20 °C for 2–6 weeks. Maceration is a chemical maturation process; reactions slow as temperature drops. Do not macerate in the refrigerator — it merely prolongs the process without benefit.
- Chilling and cold filtration
Once maceration is complete, hold the product at approximately 0–4 °C for 24 hours. Waxy structures that cannot remain in solution will precipitate; filter through filter paper while still cold. If this step is skipped, sediment will form at the bottom of the bottle on the shelf.
- Stability testing and label verification
Monitor colour, clarity, and scent drift under 40 °C oven conditions, light exposure, and freeze-thaw cycles. In parallel, finalise your allergen spreadsheet and build the INCI label directly from it.
Tip — water-based and alcohol-free versions. Baby/children's and sensitive-skin segments often call for an alcohol-free, water-based body spray. Here, solubiliser systems are needed to keep the fragrance oil clear in water. Remember: adding more water does not prevent haze — it triggers it. Hydrophobic (water-insoluble) fragrance molecules precipitate as micro-droplets as the water content rises, causing turbidity. Clarity is achieved not through water but through the correct solubiliser ratio.
A word on carrier selection: MPG (monopropylene glycol) and IPM (isopropyl myristate) are not fixatives; they are carrier solvents and emollients. They give a slight impression of fixation by marginally slowing the evaporation of alcohol — nothing more. Taking MPG above 2% will leave a tacky film on the skin. True fixation is built through macrocyclic musks, glucose ether-based fixatives, and heavy balsams/resins — most of which also happen not to appear on the declaration list, giving low-allergen formulas a secondary advantage.
Finally, set realistic longevity expectations. Longevity does not depend solely on fragrance oil concentration; what matters is the volatility profile of the raw materials. A citrus-forward 25% extrait may fade quickly, while an amber-musk-backbone 10% product may linger on skin far longer. Low-allergen formulas are inherently advantaged here because of their heavy backbone — but do not make specific hour claims.
The regulatory side has two separate headings: On one side there is process — company registration and product notification via the ÜTS system, and entry of packaging and label information into that system. On the other side there is responsibility — the obligations of the legally responsible person (responsible technical person / manufacturer), the Product Information File (PIF), and the Cosmetic Product Safety Report (CPSR). These do not substitute for one another. Note also that ÜTS company registration and product notification are subject to official fees; do not assume the only cost is the safety assessment. For current fee amounts and procedures, refer to TİTCK's applicable announcements.
Frequently Asked Questions
The questions most frequently asked in workshop sessions, with short, actionable answers. Wherever you see a figure, remember the same rule: test it in your own formula, with your own batch.
Can I write "allergen-free perfume" on my label?
Do natural fragrance oils or synthetic fragrance oils contain fewer allergens?
If I reduce the fragrance oil concentration, can I avoid allergen declaration?
Can fragrance be used in baby and children's products?
I want to use bergamot — will it cause sun spots?
If the same allergen comes from two different oils, how do I calculate it?
Will a low-allergen perfume have lower longevity?
If I have an IFRA certificate, do I still need to make allergen declarations?
Is oakmoss completely banned now?
I've written my formula in grams — how do I convert to millilitres?
How does an alcohol-free, water-based sensitive-skin spray stay clear?
Is it better to macerate in the refrigerator?
Can a cosmetic fragrance oil be used for food or aromatherapy purposes?
A low-allergen formula is not a list of rules that ties your hands — it is a discipline that simplifies your palette. Collect the documentation, do the multiplication correctly, fill the gap with an accord. The rest is your signature.
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