Potassium Sorbate, FCC
CAS No. 24634-61-5
Potassium sorbate is a food grade preservative generally regarded as safe (GRAS) worldwide. It is the inactive salt of sorbic acid. It readily dissolves in water where it converts to sorbic acid, its active form, at a low pH. Sorbic acid is very pH dependent. While it shows some activity up to pH 6 (about 6%), it is most active at pH 4.4 (70%). At pH 5.0 it is 37% active. As sorbic acid, it is considered to be active against mold, fair against yeast and poor against most bacteria. Sorbic acid is an unsaturated fatty acid and as such is subject to oxidation (use of an antioxidant like Covi-Ox T50 is recommended). It is also sensitive to UV light and may turn yellow in solution.
While sorbic acid is naturally occurring in some fruits (like the
berries of the mountain ash), virtually all of the world's production of sorbic acid, from which potassium sorbate is derived, is manufactured
synthetically from the gas ketene. It is a widely used preservative in food production, but cannot be considered "natural" (no matter what you've heard!).
Sorbic acid can cause contact dermatitis at concentrations above or below 0.5%. Studies show that if it is used at a concentration of no more than 0.2% it is unlikely to constitute a safety hazard.
Potassium sorbate is not a broad spectrum preservative for cosmetic use and should be combined with other preservates. If potassium sorbate is used as a preservative, the pH of the finished product may need to be reduced for potassium sorbate to be effective.
All cosmetic products should undergo microbial testing to ensure the efficacy of any preservative system.
At temperatures above 60°C (140°F), potassium sorbate can begin to sublime. Add to the water phase of formulations at a temperature below 60°C (140°F). If adding it after oil and water phases have been combined, predissolving the required potassium sorbate in a portion of the water phase will make it easier to incorporate into the formed emulsion.
Recommended Use Levels: 0.1% - 0.5%
Appearance: White noodles (prills)
Solubility: Soluble in water up to 58%
Storage:Store in a cool dry place away from heat or light.
INCI: Potassium Sorbate
Click here to access MSDS.
