A thickening agent or thickener is a substance which can increase the viscosity of a liquid without substantially changing its other properties. Edible thickeners are commonly used to thicken sauces, soups, and puddings without altering their taste; thickeners are also used in paints, inks, explosives, and cosmetics.

Personal care products are consumer products which are applied on various external parts of the body such as skin, hair, nails, lips, external genital and anal areas, as well as teeth and mucous membrane of the oral cavity, in order to make them clean, protect them from harmful germs and keep them in good condition. They promote personal hygiene and overall health, well-being and appearance of those body parts. Toiletries form a narrower category of personal care products which are used for basic hygiene and cleanliness as a part of a daily routine. Cosmetic products, in contrast, are used for personal grooming and beautification. Pharmaceutical products are not considered personal care products.