Lubricants: A lubricant is a substance included in a formula to reduce friction between surfaces in contact. It may also have the function of transmitting forces, transporting foreign particles, or heating or cooling the surfaces. A number of synthetic lubricants are made from petrochemical sources and are used in the cosmetic industry and in hair care products. These have negative health impacts as they can be carcinogenic and affect reproduction.
In addition to industrial applications, lubricants are used for many other purposes, include cooking (oils and fats in use in frying pans, in baking to prevent food sticking), bio-medical applications on humans (e.g. lubricants for artificial joints), ultrasound examination, medical examinations, and the use of personal lubricant for sexual purposes.