Polyethylene glycol and polyethylene oxide are polymers of ethylene oxide. Polyethylene glycol refers to the polymer with molecular weight less than 50,000, while polyethylene oxide is used for higher molecular weights.

Polyethylene glycol has the following structure:

-(CH2-CH2-O)n-

and is soluble in water, methanol, benzene, dichloromethane and is insoluble in diethyl ether and hexane.

Polyethylene glycol is non-toxic and is used in a variety of products.

Polyethylene glycol is coupled to hydrophobic molecules to produce non-ionic surfactants.