Ubiquity, Hazardous Effects, and Risk Assessment of Fragrances in Consumer Products

The main aims of fragrances are to create pleasing scents or to mask unpleasant odors. We hereby review their main exposure sources, presumed benefits, and unwanted effects, with special attention to allergic contact dermatitis (prevalence, regulatory environment, risk assessment methodology, and preventive measures).

Fragrances elicit positive emotions and presumably have therapeutic benefits related to stress reduction and memory enhancement. However, they also cause detrimental health or environmental effects including contact dermatitis (irritant and/or allergic), non-eczematous contact reactions, photosensitivity, photo-allergy, and immediate contact reactions, which can negatively impact the quality of life. Fragrances are the most frequent chemicals causing contact dermatitis. Their main sources are cosmetics, household products, industrial substances, food flavorings, oral hygiene products, and topical medications. It is difficult for sensitized patients to avoid contact with fragrances, due to their ubiquity and because manufacturers are not willing to volunteer information regarding fragrance ingredients.

The treatment of contact dermatitis relies on allergens avoidance which does not "cure" the disease (sensitization persists for life) but prevents disabling illness. The patient should understand that avoiding perfume means to avoid all scented goods and not just perfumes.Labeling fragrances is key in primary prevention (by giving the healthy individual the chance to make an informed choice to avoid risky substances), diagnosis (by helping the practitioner to plan and interpret patch tests), secondary prevention, and prognosis (by allowing the sensitized patient to follow the avoidance instructions). However, only 26 fragrances are mandatory to be declared in cosmetics. The vague labeling of other fragrance ingredients as "perfume" or "fragrance" hampers the diagnostic and preventive approaches. Therefore, in our opinion, declaration should be mandatory for all fragrance ingredients as well as straightforward so most consumers can understand it. Moreover, legislation should be improved to prevent inappropriately high exposures by forbidding stronger allergens, restricting maximum concentrations in the finished product or fields of application, delivering information regarding the risks to the general public, and controlling the compliance of manufacturers with the regulations. Besides, manufacturers should share information regarding the composition in the final products and provide physicians with samples of all fragrance chemicals whenever needed for patch test investigations.