Written on 30.03.2020. Posted in fragrance series.
What are fragrances and why are they controversial?
Fragrance substances are naturally or synthetically derived organic compounds with a characteristic, usually pleasant smell. They are ubiquitously found in perfumes and other perfumed cosmetic products, but also in detergents, fabric softeners and other household products. There, fragrances may be used to provide the consumer with a fresh smell or to mask unpleasant odours from raw materials. Fragrance substances are also used in aromatherapy and are sometimes present in herbal products. A fragrance formula (‘perfume’) may contain up to several hundred or more different ingredients. Special fragrance databases lists more than 2,587 fragrance ingredients used for perfuming.
Contact allergy to fragrance ingredients occurs when a susceptible individual has been exposed on the skin to the fragrance allergen, for example through their presence in a cosmetic product. It is a life-long, specifically altered reactivity of the immune system involving recognition of the fragrance allergen(s) by immune cells. Once a contact allergy has been developed, cells capable of recognizing and reacting towards the allergen will always be present in the immune system. As a consequence, symptoms of allergic contact dermatitis characterised by erythema (‘redness’), swelling and vesicles occur upon re-exposure to the fragrance allergen in question. If exposure continues over a longer period of time, it may develop into a chronic condition with scaling and painful fissures of the skin. Allergic contact dermatitis to fragrance ingredients is most often caused by exposure to cosmetics and predominantly involves the face, armpits or hands. The disease can be severe and generalised, with a significant impairment of quality of life and potential consequences for fitness for work. Apart from allergic contact dermatitis, fragrances in cosmetic products can also provoke irritant contact dermatitis, immediate contact reactions, pigmented contact dermatitis or photosensitivity.
A 1999 opinion by the european Scientific Committee on Consumer Safety identified 26 substances that needed to be identified on the label of consumer products to help prevent allergic reactions. Since that time, the review of the clinical and experimental data published after 1999 revealed that many more fragrance substances have been shown to be sensitisers in humans.