An Honest Look At Potassium Sorbate

This is part of our ongoing series helping consumers better understand chemicals, chemistry, and product formulations. We translate the science, bust the myths, and give you an honest assessment, so you can make informed choices for your family!

Ingredient: Potassium Sorbate

What it is: Potassium sorbate is a salt of sorbic acid which is naturally found in some fruits (like the berries of mountain ash).  The commercial ingredient is synthetically produced creating what is termed a “nature identical” chemical (chemically equivalent to the molecule found in nature).

What it does: Fights bacteria. 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!

Why we use it: Potassium sorbate is a food-grade preservative that has been effectively used for decades and is generally regarded as safe (GRAS) worldwide to preserve food products. It’s easily metabolized by the human body and doesn’t accumulate in either the body or the environment. In fact, the toxicity of potassium sorbate is comparable to that of table salt!

What’s more, it’s included in the Handbook of Green Chemicals and is also Whole Foods Premium Body Care approved. And their standards, developed by a team of scientists over the course of years, are some of the strictest available. If these two credible sources give it a thumbs-up, we do too.

Why we’re featuring it today: Some sites express concern that potassium sorbate might be carcinogenic, neurotoxic, or an endocrine disruptor. However, many studies have been conducted on potassium sorbate (it’s one of the most extensively studied preservatives) and, 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 using bacterial tests, genetic recombination tests, reversion assays, tests for chromosomal aberrations, sister chromatid exchanges, and gene mutations. 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 only legitimate health concern with this ingredient is a rare allergic reaction 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. For this reason, we always caution parents to watch for adverse reactions when using any new product.

We stand behind the safety of our products, but we’re still vigilant about new studies demonstrating risks. Science is always progressing and our understanding of the complicated world of toxicology is always expanding. Should any real risks become apparent, we’d be quick to reformulate (that’s just how we roll)!

Have any other questions or concerns about potassium sorbate? We’re happy to hear them and help you better understand this ingredient!

Reference:

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  • GatorGal15

    Thank you for addressing this issue. I know there is also much controversy over the preservative phenylethanol. After much research, many companies are re formulating to exclude this ingredient. The Honest Company uses it in only some of its personal care products, such as the hand soap. I was wondering if you could address your opinion on this ingredient as you did here with potassium sorbate.

  • http://www.fooducate.com/ Fooducate

    What about these peer reviewed studies that found issues:
    1. Does potassium sorbate induce genotoxic or mutagenic effects in lymphocytes? – YES http://www.sciencedirect.com/science/article/pii/S0887233309003853
    2. Mutagenicity and DNA-damaging activity caused by decomposed products of potassium sorbate reacting with ascorbic acid in the presence of Fe salt – http://www.sciencedirect.com/science/article/pii/S0278691502001199

    • http://blog.honest.com/ Honest

      Hello Fooducate,
      Thanks for joining the conversation! In regards to the studies you’ve shared:

      The first study found genotoxicity, but not mutagenicity. The two impacts are indeed different with mutagencity being much more concerning. Genotoxic compounds are actually much more common than you’d think — like isothiocyanates found in cruciferous vegetables and pyrrolizidine alkaloids found in comfrey tea. Scientists actually estimate that over 99% of our exposure to this class of compounds is via natural sources. Also, while in vitro studies are certainly important in helping us understand biological interactions, they cannot be so easily extrapolated to real life (in vivo) exposures. Considering exposure levels and routes is vital to understanding the potential impact of a chemical.

      The second study demonstrates toxicity after PS reacts with two other ingredients. This simply doesn’t translate to our use of PS.
      Thanks for sharing your thoughts! Please let us know if you have additional questions.

  • efrentart

    in baking can I have the ratio of the amount of potassium sorbate needed to a kilo of flour? please send me in the unit of gram.