According to research data on contact dermatitis obtained by the National Environmental Research Institute (Denmark), fragrances are one of the major causes of allergic contact dermatitis from use of cosmetics. Fragrance is a common ingredient in household products, food, cosmetics, pet care products and food, and baby care products. It is usually listed on the manufacturer's product label as an unspecified mixture of chemicals. Many of these chemicals have been linked to potential for immune and nervous system toxicity. Children are already exposed at an early age to well-known allergens, sometimes at concentrations which are considered to be unsafe.
For example, citral is widely used primarily as lemon flavoring in foods, beverages, and candies. It is also used as a lemon fragrance in detergents, perfumes, and other toiletries. Used or consumed for extended period of time, citral can instigate immune system response that can include itching, burning, scaling, hives, and blistering of skin. It is oficially classified as liver and gastrointestinal tract toxicant and eye irritant.
Other chemicals used in fragrance compounds may contain 5-methoxypsoralen, benzyl acetate, benzaldehyde, camphene, methyl ethyl ketone and many other chemical agents. Most of these chemicals are liver, kidney, nervous system, respiratory system, skin and sense organs toxicants. We all should be more concerned by the fact that the same chemical can be used in nail polish, pesticides, insecticides and candies (e.g. methyl ethyl ketone).