Fine fragrance is a type of fragrance that is used solely for its scent. It is formulated with a composition of fragrance ingredients that is the most refined. However, the fragrance industry is not required to disclose the individual ingredients that make up a products particular fragrance concoction. Fragrance suppliers have long enjoyed federal trade secret protections that allow them to hide the ingredients that make beauty and personal care products smell good. The International Fragrance Association (IFRA) published a list of 2,339 possible fragrance materials used by IFRA affiliated members, including fragrance suppliers, who use chemicals from this list or “palette” of ingredients to formulate fine fragrances and fragranced cosmetics and personal care products. Some fragrance ingredients are toxic chemicals that can cause a range of health harms. Fragrances formulated without harmful ingredients are referred to as "clean fragrances". Clean fragrances are free of parabens, phthalates, silicon, PEG, artificial dyes, BHT, BHA, and sulfates. They may also use pure and natural essential oils for their formulations, which are botanical in nature. Synthetic materials are ubiquitous today in the realm of perfumery and scented products. Fragrance oil is composed of natural extracts and natural essential oils along with laboratory-made aroma-chemicals. The density of essential oils and aroma-chemicals may be harsh to the skin, so a solvent is added to ease the application and create a sillage.