Polysorbate 20

What it is

Polysorbate 20 is made by attaching about 20 ethylene oxide units to sorbitan monolaurate, a sugar-alcohol ester of lauric acid. The result is a mild, non-ionic surfactant that likes both water and oil. It is used at low levels to keep essences clear, disperse fragrance, and help wash-off products lift oily residues: of the thirteen masks here whose list shows the point where ingredient order stops indicating quantity, eleven print it below that point.

What it does well

• Keeps clear formulas clear

  It reliably solubilises small amounts of oil, fragrance or oil-soluble actives into water-based liquids, which is why it is a fixture of essences, micellar waters and sheet-mask serums.

  Strong evidence

• Non-ionic surfactants like this are among the gentler cleansing and dispersing agents

  In cell-based irritation screening, non-ionic surfactants activated the skin's TRPV1 irritation pathway far less than classic anionic surfactants, consistent with their long record in leave-on products.

  Moderate evidence

Worth knowing

• Uncommon hypersensitivity in people already sensitised to polysorbates or PEGs

  Delayed allergy to polysorbate confirmed by patch testing is documented, and polysorbate 80 has been linked to non-immunologic anaphylactoid reactions when injected. Topical cosmetic exposure at low percentages is a much lower-risk situation than injection, but it is relevant if you have a diagnosed excipient allergy.

  Matters most toPeople with a confirmed polysorbate or PEG allergy from an allergy work-up.

• Shares the ethylene oxide / 1,4-dioxane residue question with PEGs

  Polysorbates are ethoxylated, so the same trace 1,4-dioxane discussion applies. The EU handles it by prohibiting 1,4-dioxane and ethylene oxide outright and allowing only technically unavoidable traces.

  Matters most toConsumers deciding whether ethoxylated ingredients are a problem; on current evidence, at cosmetic trace levels, they are not.

Where the EU stands

Sources (3)

Every link goes to the original: a journal, a PubMed record or an EU document.

1. [1]
   A case of delayed allergy to polyethylene glycol 2000 and polysorbate 80 confirmed by patch test: Consequences for anti-SARS-CoV2 vaccination?

   Contact Dermatitis · 2022 · doi:10.1111/cod.14131

   Delayed-type allergy to polysorbate 80 and PEG was confirmed by patch testing, showing such reactions exist but are documented as individual cases.

2. [2]
   Polysorbate 80 in medical products and nonimmunologic anaphylactoid reactions

   Annals of Allergy, Asthma & Immunology · 2005 · doi:10.1016/s1081-1206(10)61024-1

   Polysorbate 80 can trigger non-immunologic anaphylactoid reactions in medical products, a route-of-exposure risk chiefly relevant to injectables rather than topical cosmetics.

3. [3]
   The Role of TRPV1 Channel in Cosmetic Safety Evaluation

   ACS Omega · 2026 · doi:10.1021/acsomega.5c10830

   Non-ionic surfactants were among the mildest categories tested in a TRPV1-based skin irritation screen.