Optiphen Preservative distributed by Wasatch Naturals is a mild yet very effective preservative used in cosmetic products such as lotions, balms, serums, and more. Optiphen is paraben-free and formaldehyde free. Optiphen provides a broad spectrum preservation against bacteria, yeast, and mold. Ashland Chemical is the manufacturer and owner of the trademark Optiphen. Recommended use is .5% to 1.5%. We offer Optiphen in three main sizes 2 oz, 4 oz, and gallon