Preservatives in Oil-Based Formulas

For cosmetic formulations that contain only oil and no water, traditional preservatives (which prevent microbial growth) are generally not necessary. Microorganisms require water to survive and multiply.

The primary concern for oil-based products is oxidation, which can lead to rancidity and degradation of the oils. To prevent this and extend the shelf life of your oil formula, you should use antioxidants.

Antioxidants work by preventing or slowing down the oxidation process. Here are some suitable antioxidants for oil-based formulas:

• Protec™ OX (Pentaerythrityl tetra-di-t-butyl hydroxyhydrocinnamate): A highly effective antioxidant that helps protect ingredients from deterioration caused by free radicals and oxidation. It is soluble in oil, requiring heat (70-80°C) to dissolve.
• tert-Butylhydroquinone (TBHQ): A common antioxidant used to maintain the quality of ingredients in formulas. It can be dissolved in Glycol or Ethanol before adding to formulations.
• Astaxanthin (10% Algae Extract, Oil): A powerful antioxidant in an oil-soluble liquid form, suitable for oil-based products like balms and oils. It helps protect against oxidative damage.
• Dimethylmethoxy Chromanol (1%, Oil Based) and ChromaDetox™ (Dimethylmethoxy Chromanol): These are potent antioxidant molecules that are more effective than Vitamin E at preventing the oxidation of natural oils. Both are soluble in oil; the 1% Oil Based version is a liquid, while ChromaDetox™ is a powder. It is recommended to add them in the oil phase, avoiding heat.

Choose an antioxidant based on its solubility profile, required usage rate, and compatibility with your specific oils and formulation process.