Propanediol

Propanediol is a type of alcohol that contains two alcohol groups. The two alcohol groups result in the term “diol.” This specific diol is an excellent solvent due to having both water-loving alcohol groups and oil-loving carbon chains, so it is capable of combining water with normally water-insoluble ingredients.

Due to its water-loving alcohol groups, propanediol also functions as a humectant. This means the alcohol groups attract water to the surface of the skin, creating greater moisturization.

In addition, propanediol can control viscosity of a product by reducing the thickness of it.