7. Conclusion : are the current European regulations on fragrance allergens adequate?
- 7.1 Is the current list of possible allergens adequate ?
- 7.2 Is there a threshold of safe use for these allergens?
- 7.3 Are there other substances that are relevant for consumers regarding perfume allergies?
7.1 Is the current list of possible allergens adequate ?
The SCCS opinion lists a number of individual substances and natural extracts considered as ‘established contact allergens in humans, ‘established contact allergens in animals’ or ‘likely contact allergens by combination of evidence’. The selection is made based on a comprehensive screen of available clinical and animal data, paired with computer-based SAR modelling where appropriate.
The SCCS considers that these substances represent those fragrance ingredients that the consumer should be made aware of when present in cosmetic products. Substances known to be transformed into known contact allergens (for example by hydrolysis of esters) should be treated as equivalent to these known contact allergens. The combined concentration of the alcohol and its ester must be considered regarding exposure. Important examples include isoeugenol and its esters, geraniol and its esters, eugenol and its esters, and linalool and its esters. More...
7.2 Is there a threshold of safe use for these allergens?
There are two components to the safety of fragrance ingredients in terms of contact allergy: (i) the need to eliminate or reduce induction of contact allergy (primary prevention), which, when it occurs, is lifelong and (ii) the need to eliminate or reduce elicitation reactions (secondary prevention) on the skin of those individuals who are already sensitised.
Based on available data, the SCCS could not establish thresholds of safe use for individual fragrance allergens. However, they concluded that a general level of exposure up to 0.8 μg/cm2 (0.01%) may be tolerated by most consumers with contact allergy to fragrance ingredients. The SCCS considers that this level of exposure could be efficient in limiting elicitation unless there is substance-specific data, either experimental or clinical, to the contrary. Such a threshold based on elicitation levels in sensitised individuals will be sufficiently low to protect both sensitised individuals as well as most of the non-sensitised consumers from developing contact allergy.
It was not possible to provide a safe threshold for natural extracts of concern, as no specific investigations exist and the model providing the general threshold has been based on individual chemicals only. However the SCCS considers that the maximum use concentration applies to the above-identified fragrance allergens also when present in the natural extract. This will also reduce the risk of sensitisation and elicitation from natural extracts.
It is important to stress that this general threshold, although limiting the problem, does not preclude that the most sensitive segment of the population may react upon exposure to these levels. Hence, this threshold does not remove the necessity for providing information to the consumer concerning the presence of the fragrance substance in cosmetics.
In the case of hydroxyisohexyl 3-cyclohexene carboxaldehyde (HICC), the SCCS considers that the number of cases of allergy documented over the last decade is exceptionally high and that continued exposure by the consumer is not safe. Therefore, HICC should not be used in consumer products.
In accordance with the 2004 recommendation of the Scientific Committee on Consumer Products (SCCP), the SCCS is of the opinion that chloroatranol and atranol, the main allergenic constituents of Evernia prunastri (oakmoss) and Evernia furfuracea (treemoss), should not be present in products for the consumer. More...
7.3 Are there other substances that are relevant for consumers regarding perfume allergies?
Many fragrance substances can act as prehaptens or prohaptens, forming allergens which are more potent than the parent substance by abiotic and/or metabolic activation. Activation can thus increase the risk of sensitisation. Fragrances with published data showing the formation of sensitising compounds by autoxidation, bioactivation or both include:
- Limonene, linalool and linalyl acetate, known to be prehaptens and form sensitising compounds by air oxidation;
- Cinnamyl alcohol, eugenol, isoeugenol and isoeugenyl acetate, known to be prohaptens and form sensitising compounds by metabolic transformation;
- Geraniol and alpha –terpinene, known to be both prehaptens and prohaptens;
- Geranial (an isomer of citral) is a sensitser without activation but forms more potent sensitising compounds by air oxidation and also by metabolic transformation.
The SCCS is of the opinion that substances known to be transformed to known contact allergens should be treated as equivalent to these contact allergens. The same restrictions and other regulatory requirements should apply, unless specific data exist that allow for an individual assessment. More...