PEG-18 is derived from vegetable sources (coconut oil) this ingredient is an emulsifying agent.
Emulsifiers are used in Bellatorra products to mix water with oils. Since water and oil do not mix but stay separated, an additional agent (emulsifier) is necessary to form a homogenous mixture keeping water and oil together. There are 2 types of emulsifier: Oil-in-water (o/w) emulsifiers keep oil drops packed in water, while water-in-oil (w/o) emulsifiers keep water drops packed in oil. PEG-18 Glyceryl Oleate/Cocoate is an o/w emulsifier.