CosmeticBet
Preservatives

Potassium sorbate

INCI: POTASSIUM SORBATE

A food preservative that keeps out yeasts and moulds.

drag to turn
C6H7KO2150.22 g/mol
potassiumoxygencarbon
2D drawing from PubChem 23676745 (hydrogens hidden)

How common

All products15%
In shower gels29%
In face moisturisers29%
In shampoos23%

2,258 of 14,784 products with a full ingredient list in Open Beauty Facts; No. 16 of all the names found on their labels.

What it is

  • The potassium salt of sorbic acid (hexa-2,4-dienoic acid).

    2 sourcesHide
    Potassium sorbate is a potassium salt having sorbate as the counterion.[1] PubChem (US National Library of Medicine) · open source
    4 Hexa-2,4-dienoic acid and its salts Sorbic acid, calcium sorbate, sodium sorbate, potassium sorbate[2] EU law · 2026 · open source

Why it is in products

  • To preserve the product, above all against yeasts and moulds. Sorbic acid preserves many foods as well.

    2 sourcesHide
    is an antimicrobial agent against a wide variety of microorganisms, especially yeasts and moulds[1] PubChem (US National Library of Medicine) · open source
    (2E,4E)-2,4-Hexadienoic acid is a preservative for many foodstuffs.[1] PubChem (US National Library of Medicine) · open source

What it does

  • It works better in acidic products: the pH sets how much of the acid is in the uncharged form that can get into germs.

    Some evidence3 sourcesHide
    is a preservative action more efficient in acidic foods[1] PubChem (US National Library of Medicine) · open source
    pH is considered to be a major determinant of the organic acids’ effectiveness because it affects the concentration of formed undissociated acids[3] Study · 2018 · open source
    Uncharged molecules are those forms that enable the penetration of organic acids into the cell[3] Study · 2018 · open source

Downsides and safety

  • Considered a rare skin allergen, though allergy to it may be underestimated. Products with potassium sorbate always contain some sorbic acid, so people allergic to sorbic acid should avoid them.

    Some evidence4 sourcesHide
    The preservatives sorbic acid (SA) and potassium sorbate (PS) are considered rare skin sensitizers.[4] Study · 2021 · open source
    Sensitization to SA and PS is probably underestimated.[4] Study · 2021 · open source
    PS-containing products always contain SA to a certain extent[4] Study · 2021 · open source
    patients sensitized to SA should avoid PS-containing products[4] Study · 2021 · open source

  • Some moulds can break it down: certain Penicillium species turn sorbic acid into 1,3-pentadiene.

    Some evidenceSourceHide
    sorbic acid may be degraded to 1,3-pentadiene by some species of Penicillium[3] Study · 2018 · open source

Where it works

Works insidethe product

It works in the product, keeping yeasts and moulds from growing there.

SourceHide
is an antimicrobial agent against a wide variety of microorganisms, especially yeasts and moulds[1] PubChem (US National Library of Medicine) · open source

Rules

European Union

  • Allowed as a preservative up to 0.6% (counted as the acid).

    SourceHide
    Sorbic acid, calcium sorbate, sodium sorbate, potassium sorbate 110-44-1, 7492-55-9, 7757-81-5, 24634-61-5 203-768-7, 231-321-6, 231-819-3, 246-376-1 0,6 % (acid)[2] EU law · 2026 · open source

United States

  • Not on the FDA’s list of prohibited or restricted cosmetic ingredients. In the US, cosmetics and their ingredients (other than colour additives) don’t need FDA approval before sale.

    SourceHide
    Under U.S. law, cosmetic products and ingredients, other than color additives, do not need FDA approval before they go on the market[5] US Food and Drug Administration · open source
    We searched the FDA’s list of prohibited and restricted cosmetic ingredients: no entry.open the list

Sources

  1. PubChem: Potassium sorbate (CID 23676745), record description PubChem (US National Library of Medicine)PubChem (US National Library of Medicine)
  2. Regulation (EC) No 1223/2009 on cosmetic products, consolidated text of 18 May 2026 Publications Office of the European Union (EUR-Lex/Cellar), 2026EU law
  3. Cosmetics Preservation: A Review on Present Strategies Molecules : A Journal of Synthetic Chemistry and Natural Product Chemistry, 2018Study
  4. Allergic contact dermatitis from potassium sorbate and sorbic acid in topical pharmaceuticals and medical devices Dendooven E et al., Contact dermatitis, 2021Study
  5. Prohibited & Restricted Ingredients in Cosmetics | FDA US Food and Drug Administration

Checked against these sources on 4 November 2026. Spot a mistake? Tell us.