I’ve been trying out some new natural skincare products lately. As always, I was skeptical of the claims that the products were totally natural because of some confusing, uncommon ingredients I needed to look-up first. To me, potassium sorbate just sounded a bit suspicious. So what is it and is it really a “natural” ingredient?
Potassium sorbate is a chemical compound produced as a result of a chemical reaction between potassium hydroxide and sorbic acid. It is the potassium salt of sorbic acid, a naturally occurring antimicrobial compound used as a preservative.
“Potassium sorbate is a salt of sorbic acid which is naturally found in some fruits” 
This compound appears as a white or white-yellowish crystalline powder whose slightly high acidic nature accounts for its antimicrobial properties.
Potassium sorbate is commonly used as a preservative in food products due to its ability to inhibit microbial growth thus reducing the risk of disease and increasing shelf life of food items. Food items such as “dairy products, baked goods, beverages, cured fish and meats, vegetable and fruits as well as confections” are products for which potassium sorbate is often used. Potassium sorbate also plays a role in the production of wine. After the fermentation process, active yeast still exists within the wine. Potassium sorbate is added to keep the wine’s flavor and body as well as to inhibit further yeast growth.
Within personal care products, potassium sorbate can be found in many shampoos, conditioners, lotions and cosmetics to prevent the growth of molds and fungi and to extend shelf life.
Regarding industrial uses, potassium sorbate is also used in improving the gloss of certain coatings, in manufacturing lubricants and plasticizers as well as perfects the milling characteristics of rubber. Potassium sorbate is inexpensive to produce, is easily metabolized by the human body, doesn’t accumulate in the body or environment and has a low toxicity in humans.
Through extensive testing and studies, the U.S. Food and Drug Administration has deemed potassium sorbate safe for use as a food preservative. There have been many concerns regarding potassium sorbate yet most studies found that the only legitimate health concern is rare allergic reaction or sensitivity resulting in migraines or diarrhea.
“Some sites express concern that potassium sorbate might be carcinogenic, neurotoxic, or an endocrine disruptor. However,[…] according to an exhaustive review published in the International Journal of Toxicology, the findings reveal: Potassium sorbate, at concentrations up to 10%, is practically non-irritating to the eye and only slightly irritating to skin. Potassium sorbate has been tested for mutagenic effects[…]The weight of evidence indicates that it is not mutagenic. Potassium sorbate at 0.1% in the diet or 0.3% in drinking water for up to 100 weeks was not carcinogenic. No developmental effects have been observed. Formulations containing up to 0.5% were not significant primary or cumulative irritants and not sensitizers. Currently, the legitimate health concern with this ingredient is a rare allergic reation or sensitivity (that could lead to migraines or diarrhea). But even that type of reaction can vary from formulation to formulation, so some products might cause irritation, while others don’t.” 
The EWG’s Skin Deep database ranks potassium sorbate with a score of 3 due to data gaps and the evidence that it may produce organ system toxicitiy (non-reproductive) and is a human skin toxicant or allergen.
“Potassium sorbate is well-tolerated in most people, being easily metabolized. Allergic reactions are rare.” 
As always, maintain extra care or caution if you are using skincare or other personal care products with potassium sorbate especially if you have sensitive skin. I choose to use certain products with naturally-derived preservatives because I believe that to a certain point, there is a need to keep products safe and bacteria-free.
I think The Honest Company’s explanation for using potassium sorbate and other natural preservatives says it best:
“Most personal care products are made with a lot of water and a variety of nutrients (consider all of the natural oils and botanicals in Honest products!) which makes an incredibly hospitable breeding ground for microorganisms. What’s worse – the product might smell and look just fine, but be swarming with bacteria or fungi that are dangerous to your health. Effective preservatives are vital for ensuring safety!” 
Do you use any products that contain potassium sorbate? What is your opinion on preservatives or alternative preservatives?
Image source: Epochemical