Optiphen PLUS is a Natural Preservative. Optiphen+ is a unique paraben-free and formaldehyde-free liquid preservative system which consists of Phenoxyethanol in an emollient base of Caprylyl Glycol. The combination of these ingredients provides optimized protection against microbial growth while imparting exceptional feel to the finished product. Optiphen is a clear liquid preservative that can be easily added directly to the formulation during pre- or post-emulsification at or below 60 degrees C(140 degrees F). There are no ph restrictions in formulating with Optiphen. Optiphen is compatible with most ingredients used in the personal care industry.