Cosmetic Allergen Management & the 26-Allergen Labelling Rules (Now 80+)

Before a fragrance enters the bottle, it is the balance of countless molecules. Some of those molecules can trigger contact allergy (contact dermatitis) in sensitive skin. This is precisely what regulations call "declaration": the obligation to inform consumers about what they may need to avoid.

First, let us dispel a critical misconception. The perception that "natural is safe, synthetic is risky" is the most frequently repeated error in the industry — and it is legally dangerous. A significant proportion of declarable allergens are found at the highest levels in natural essential oils. Fragrance allergens can be present in both synthetic and natural ingredients; not only synthetic fragrances, but also natural extracts and essential oils may contain these substances. Safety depends not on the source but on the molecule and the level of use.

Another critical point: some substances are not potent allergens in their pure form, but become strong sensitisers upon oxidation (when they oxidise on contact with air). Limonene and linalool are not potent allergens in their pure form, but become potent sensitisers upon oxidation. For this reason, regulations also treat prehaptens and prohaptens — substances that can be converted into known contact allergens through air oxidation or bioactivation — as equivalent to allergens and subject them to the same restrictions.

For years, the phrase "26 allergens" became embedded in the industry's vocabulary. That number is now consigned to history. This is the most up-to-date reality that any producer or prospective seller must know.

In 1999, the SCCNFP — now known as the SCCS (Scientific Committee on Consumer Safety) — identified 26 fragrance substances that must be declared on labels to prevent allergic reactions. Science, however, has moved on. Commission Regulation 2023/1545 significantly expands the list of declarable fragrance allergens from 26 substances to over 80.

The precise number varies between sources: the total can change depending on how groups are counted; since some entries cover families of related substances, many expert sources use the term "80+ allergens" rather than a fixed figure. In practice, the regulation introduces 56 new fragrance allergens based on SCCS assessment.

This is where producers most commonly go wrong. The threshold looks not at the proportion of an allergen within the fragrance oil, but at the final proportion in the finished product. The rule is simple: multiply first, then compare against the threshold.

Distinguish between two categories: for rinse-off cosmetics (soap, shower gel, shampoo) the threshold is 0.01%; for leave-on cosmetics (cream, lotion, toner) the threshold is 0.001%. The threshold always applies to the concentration in the finished product, not in the fragrance compound itself.

The biggest blind spot for producers working with essential oils: natural oils are assumed to be "clean," yet they are often the primary source of allergen load.

Fragrance allergens are not limited to synthetic fragrance compounds; they are also found naturally in many botanical ingredients. Essential oils and plant-derived extracts may contain allergenic substances subject to the same labelling requirements. For this reason, botanical oils should be accompanied by documentation such as an IFRA certificate and allergen content information where applicable.

Concrete examples: citrus oils contain high levels of Limonene and Citral; lavender and many floral oils contain high levels of Linalool and Geraniol; clove contains high levels of Eugenol. Additionally, natural bergamot is phototoxic — it causes pigmentation (photodermatitis) on skin exposed to sunlight. The assumption that "it's natural, therefore risk-free" is therefore dangerous.

Build your formulas on a gram (g) basis — this is correct practice. However, do not equate grams directly with millilitres. The specific gravities of fragrance oils and solvents vary considerably: a citrus-dominant fragrance oil is approximately 0.84 g/ml, while heavy resins or certain synthetics can exceed 1.10 g/ml. The same weight in grams can represent very different volumes.

All of these calculations and documents come together in one place: the PIF (Product Information File). When regulations change, documentation must change with them. Part A (formula, exposure assessment) and Part B (safety assessment) of the Product Information File must be updated with new toxicological data, and the expanded fragrance allergen list must be applied to the label. This topic is closely intertwined with our articles on CPSR / Cosmetic Safety Assessment and Stability and Challenge Testing — because an oxidised limonene affects both allergen load and product stability.

This final section is practical: timelines, responsibility, and what you need to look at in Turkey. The rest depends on your own diligence.

The transition period on the EU side is now clear. Products placed on the EU market must comply with these requirements by 31 July 2026; products already on the market that do not comply may continue to be sold until 31 July 2028. Distinguish between these two concepts: "placing on the market" means the manufacturer's or importer's first making the product available in the EU; "making available on the market" refers to every subsequent distribution, such as retail sale.

Responsibility: The Responsible Person for a cosmetic product is responsible for keeping these notifications up to date. The process (notification steps) and accountability (Responsible Person/manufacturer obligations) are therefore distinct concepts. Non-compliance carries serious consequences: non-compliance may result in products being held at customs or refused entry to the EU market.

The Turkey dimension: Turkish cosmetics legislation broadly tracks EU Regulation 1223/2009; the expansion introduced by 2023/1545 is therefore expected to be reflected in domestic implementation. However, for the current declarable substances list, ÜTS company registration, and product notification obligations in Turkey, the definitive and up-to-date source is TİTCK. ÜTS company registration and product notification are subject to official fees; do not budget on the assumption that "notification is free" — the cost goes beyond the safety assessment alone.