Mono Propylene Glycol is a viscous colourless liquid which is nearly odourless but possesses a faintly sweet taste.Forty-five percent of propylene glycol produced is used as chemical feedstock for the production of unsaturated polyester resins. Propylene glycol is used as a humectant, solvent, and preserva-tive in food and for tobacoo products. Propylene glycol is used as a solvent in many pharmaceu-ticals, including oral, injectable and topical formulations.