Propylene glycol (1,2-propanediol)" refers to a bivalent alcohol that is widely used in pharmacy, cosmetics and technology due to its chemical and physical properties, both as a monosubstance and as a component of ester compounds. "isoceteth-3" refers to a polyoxyethylene ether of isocetyl alcohol. The hydrophilic part is formed by short-chain polyethylene glycols (polyoxyethylenes). The numbering after isoceteth-12 indicates the average number of ethylene oxide units per mole, in this case 12 ethylene oxide units per mole.
Propylene glycol isoceteth-12 acetate is used in cosmetic formulations. The substance acts as an emulsifier (surface-active substance that is used in cosmetic products as an additive to combine 2 immiscible liquids - e.g. oil and water - to form an emulsion).