Said to be a natural antibacterial, antimicrobial, & antifungal compound which can be used as an effective preservative in cosmetics and foods. Technically however this product is an antioxidant. Please see Antioxidants versus Preservatives for more information on this topic. Derived from the seed and pulp of grapefruit. Usage is typically .1% to 1%. Grapefruit Seed Extract 60%/ Glycerin USP 40% For more information on this product please go to CITRICIDAL