As defined by NICNAS, A 'cosmetic' is a substance or preparation that is for use on any external part of the human body—or inside the mouth—to change its appearance, cleanse it, keep it in good condition, perfume it or protect it. Cosmetics include soap, shampoo and conditioner, moisturiser, 'bath bombs', hair dye, perfume, lipstick, mascara, nail polish, deodorant and many other products.

Nearly all cosmetic ingredients are regulated as industrial chemicals under the Industrial Chemicals (Notification and Assessment) Act 1989 (ICNA Act). This includes ingredients described as 'natural' or 'organic' such as oils, extracts and plant essences.