C3H8O3 – glycerol – is a colorless, odorless, viscous, non-toxic liquid. Its ability to absorb water from the air makes it useful in products (some soaps, skin care products, shaving creams, hair gels, etc) meant to keep skin smooth and moisturized. It is also used as an ingredient in fog machines! The fog is created by blending water and glycerin-based fluids, and the mixture is then heated and expelled from the fog machine. It cools as it comes into contact with the outside air and turns into an aerosol, creating a dense, visible fog.