Porecelain

Flawless skin starts with the fine print.

Polysorbate 20

Polysorbate 20 is rated Clear, at Low confidence. Two rabbit-ear laboratories put a number on the material actually named on the label, and both printed 0 on a 0 to 5 scale: Fulton in 1989, and Morris and Kwan in 1983. The second was tested at 1% in water and the first at roughly 10% in propylene glycol, which is not a matched pair of conditions, and both are rabbit ears. We identified no human comedogenicity study of it.

Clear Low confidence Legacy score 0 on a 0-5 scale · Fulton 1989 · low reliability

Fulton 1989 scored 0 and Morris and Kwan 0 at 1% aqueous — different exposures, same digit.

What it is

A nonionic surfactant used to emulsify and, more often, to solubilise. It lets a small quantity of oil, fragrance or an oil-soluble active disperse into a water-based formula and stay there. On a label it is Polysorbate 20. Chemically it is polyoxyethylene (20) sorbitan monolaurate, sold for decades under the trade name Tween 20, CAS 9005-64-5. SpecialChem's ingredient entry gives its chemical name as sorbitan monododecanoate, poly(oxy-1,2-ethanediyl) derivatives, monododecanoate being another name for monolaurate, the twelve-carbon fatty acid. The ethylene-oxide chains make it strongly water-loving, which is why it works on the water side of a formula rather than as an emollient. The name is a specification rather than one molecule. The commercial material is a mixture of partial esters of sorbitan and its anhydrides, ethoxylated to a nominal total of about twenty ethylene-oxide units, with lauric acid as the nominal fatty part. How approximate "nominal" is has been measured at least once. A 2025 Utrecht mycology group, needing Tween as a lipid source for culturing yeasts, ran gas chromatography on its own bottles of Tween 20, 40, 60 and 80 and reported that none was pure, and that Tween 20 in particular carried several fatty acids at once, mostly lauric and myristic with smaller amounts of palmitic, stearic and oleic. That is one laboratory characterising its own reagent, not a survey of cosmetic grades, but it is a measurement, and it is worth holding while reading any score attached to this name. Two neighbours are easy to run together with it, and both are rated separately here. Polysorbate 80 is the same architecture built on oleic acid instead of lauric. Sorbitan laurate, sold as Span 20, is the plain un-ethoxylated sorbitan monolaurate that Polysorbate 20 is built from.

Why we rate it Clear

We rate it Clear, at Low confidence. The evidence is two legacy rabbit-ear readings, and being precise about what each one is, and how the two differ, is most of this page. The first number. James Fulton's 1989 survey in the Journal of the Society of Cosmetic Chemists is the source of a large share of the comedogenic scores in circulation. His method: the ingredient at roughly 10% in propylene glycol, 1 ml applied to the inner ear of three New Zealand albino rabbits, five days a week for two weeks, follicles then read for keratosis. The row labelled "Polysorbate 20" reads 0, on a 0 to 5 scale. It carries no asterisk, and it does not sit in the paper's oils section, so the "results depend on source of raw material" caveat that governs the oils and butters does not ride on it. By Fulton's own key, printed in his methods and quoted far less often than his numbers, a grade of 0 to 1 "is not considered significant." The second number, and how it differs. Morris and Kwan's 1983 rabbit-ear study is a different laboratory, six years earlier, and it contradicts Fulton in print on several other materials. It has a Polysorbate 20 row too, and that row also reads 0 on a 0 to 5 scale. Their substances were applied undiluted unless the table said otherwise. For this one the table said otherwise: 1% aqueous. Fulton read his row at roughly 10% in propylene glycol, so the two 0s were taken at different concentrations in different carriers. That is not a matched-condition replication, and we hold no document calibrating this model against concentration, so we state the difference and stop there. Two readings, one answer, conditions that do not match. Material identity. Most of the notorious numbers on this site turn out to belong to a material sitting beside the one on the label: a butter read as an oil, a derivative read as its parent. This is not one of those. Both papers print a row headed Polysorbate 20, and both read 0. What the score does not follow from. Polysorbate 20 is a laurate, and lauric acid is the fatty acid the legacy tables treat worst. Fulton scored lauric acid 4 and laureth-4 5 on his 0 to 5 scale, and in his conclusion he named "the major offenders, such as isopropyl myristate, acetylated lanolin alcohol, and lauric acid derivatives such as laureth-4" as ingredients to use with caution. Yet in the same table the other laurates run the length of the scale: laureth-23 at 3, PEG 200 dilaurate at 3, sorbitan laurate at 1 to 2 with his asterisk, PEG 40 sorbitan laurate at 0, and Polysorbate 20 at 0. Inside one laboratory's own ingredient set, then, "it is a laurate" does not predict the grade, and we are not going to supply a mechanism the paper does not. Fulton's prose runs the other way for a different family: he wrote that the classic anhydrous lanolins are not as comedogenic as the moderately ethoxylated derivatives. We report the rows and decline the causal story. Where a reader meets the number. Consumer ingredient references generally print 0 for Polysorbate 20 or simply call it non-comedogenic, usually without naming a measurement. SpecialChem's entry, cited below, is a fair example: it states flatly that the ingredient is non-comedogenic and gives no source for it. In this case the underlying readings do exist, and they are the two above. We identified no primary document that assigns Polysorbate 20 anything other than 0.

What the evidence doesn’t tell you

Both readings are rabbit ears, from 1983 and 1989, and a rabbit's ear canal is not a human face. Fulton called his own survey "not at all definitive but simply designed to stimulate research," and warned that the model is sensitive enough that not everything which irritates it will irritate human skin. We identified no human comedogenicity study of Polysorbate 20 in either the legacy corpus or the current literature. Two further primary inventories carry nothing on it: Fulton's earlier 1984 table has no Polysorbate 20 row, and the materials named in Nguyen, Dang and Maibach's 2007 rabbit assay do not include it. The two readings were not taken under matched conditions. Morris and Kwan tested this material at 1% in water; Fulton tested at roughly 10% in propylene glycol. That is a difference in concentration and in carrier, and we hold no document that calibrates this model against either, so we report the difference and leave it there rather than converting it into a weight. Neither reading is about a formula. An isolated-ingredient score describes the raw material, not the product it is dispersed inside. Draelos and DiNardo's 2006 re-evaluation reported finished products testing non-comedogenic despite containing ingredients the rabbit assay had flagged, and a 2025 review in JAAD Reviews found that no standardised comedogenicity test exists and that "non-comedogenic" is an unregulated label. A low rabbit score is a reason to hold the concern lightly, not a guarantee for a given face at a given concentration. The expert-panel safety assessment is not evidence here. The Cosmetic Ingredient Review's 1984 final report on the polysorbates concluded they are safe as used in cosmetics. That is a safety conclusion, and safety is a different question from follicular plugging. We cite it for identity and use, not for the rating. The caution a reader is most likely to meet is not a comedogenic one, and it is worth naming exactly. Polysorbate 20 appears on fungal-acne, or Malassezia, avoidance lists. Malassezia yeasts cannot make their own saturated fatty acids and are cultured on lipid-rich media, and Tween is one of the standard lipid sources used to do it. The Utrecht group's 2025 paper is the clearest measurement of that we found: growing two species, Malassezia furfur and Malassezia pachydermatis, in defined broth with 0.1% Tween as the only fatty-acid source and a non-ionic co-detergent present, they reported efficient growth on Tween 20, 40, 60 and 80, and wrote that "growth on Tween 20 is very efficient." That is a real finding and it is not a comedogenicity finding. The endpoint was optical density in a 96-well plate over 72 hours; no skin was involved and no comedone was counted. Malassezia folliculitis is in any case a different condition from the comedones this rating is about. We identified no study measuring comedones, or folliculitis, on human skin after topical Polysorbate 20. Unproven is not disproven: a reader whose problem is fungal has a reason to be cautious that this page cannot settle either way.

Where you’ll see it

On a label it is Polysorbate 20. It turns up where a little oil or fragrance has to go into water: facial cleansers and micellar waters, toners and sprays, light serums and lotions, sunscreens, and colour cosmetics. It is also familiar from outside skincare, as the food additive E432 and as a common pharmaceutical excipient under the Tween 20 name. The categories here are illustrative rather than a market survey we have run. Polysorbate 80 and sorbitan laurate are rated separately and should not be read off this page.

Sources

Each source says what it actually is. Several widely-cited “sources” for comedogenic ratings are republishing the same 1989 assay, and counting them as independent agreement is how a thin evidence base gets made to look thick.

  1. Fulton JE. "Comedogenicity and irritancy of commonly used ingredients in skin care products." J Soc Cosmet Chem 40:321-333 (1989) A 220-row rabbit-ear survey, and the origin of a large share of the comedogenic numbers online. Read here off a render of the journal scan rather than from a list quoting it. Method: ingredient at roughly 10% in propylene glycol, 1 ml applied to the inner ear of three New Zealand albino rabbits, five days a week for two weeks, follicles scored for keratosis on a 0 to 5 scale. Its "Polysorbate 20" row reads 0, with no asterisk and outside the asterisked oils section. The same table prints lauric acid 4, laureth-4 5, laureth-23 3, PEG 200 dilaurate 3, sorbitan laurate 1 to 2 with an asterisk, and PEG 40 sorbitan laurate 0. Fulton's methods define 0 to 1 as "not considered significant," and he called the whole survey "not at all definitive." An animal reading from 1989, not a measurement on human skin, and not a test of any formula.
  2. Morris WE, Kwan SC. "Use of the rabbit ear model in evaluating the comedogenic potential of cosmetic ingredients." J Soc Cosmet Chem 34:215-225 (1983) A second rabbit-ear laboratory, six years before Fulton, working in the external ear canal of three rabbits over 14 applications with microscopic grading only, on its own 0 to 5 scale. It openly contradicts Fulton on several materials and says so in print, which is why it is not a republisher of him. Its 32 rows include five surfactants, among them "Polysorbate 20 (1% Aqueous)" at 0. Substances were undiluted unless the table stated otherwise, and for this row it did: the reading is of a 1% solution in water, against Fulton's roughly 10% in propylene glycol. Cited as a genuinely separate measurement of this material, taken under conditions that do not match his.
  3. Liebregts J, van der Velden L, Fonseca-Fernandez AL, Celis Ramirez AM, de Cock H. "Lipid-dependent growth of Malassezia spp. in defined medium with single fatty acids." FEMS Yeast Res 25:foaf043 (2025) A fungal-culture methods paper from Utrecht University, cited in the limits section and not for any comedogenic number. It develops a defined growth medium for Malassezia and, along the way, grew Malassezia furfur and Malassezia pachydermatis on 0.1% Tween 20, 40, 60 and 80 as the sole fatty-acid source, with a non-ionic co-detergent present, reporting efficient growth on all four and noting that growth on Tween 20 is very efficient. Its endpoint is optical density in a 96-well plate over 72 hours; it counts no comedones and involves no skin. It is also the source of the statement used here that Malassezia cannot synthesise saturated fatty acids de novo and must be cultured on lipid-rich media. It is also the source of the gas-chromatography finding that its own Tween reagents were not pure, Tween 20 carrying lauric, myristic, palmitic, stearic and oleic acids. It cannot support any claim about pores.
  4. Elder RL (ed.). "Final Report on the Safety Assessment of Polysorbates 20, 21, 40, 60, 61, 65, 80, 81, and 85." J Am Coll Toxicol 3(5):1-82 (1984) An expert-panel safety assessment concluding the polysorbates are safe as used in cosmetics. What we read is the 1984 report as published in J Am Coll Toxicol; we have not read any later amended version of it and do not describe one here. It assesses safety and says nothing about follicular plugging. Cited for chemical identity and for confirming widespread cosmetic use, not as evidence for a comedogenic rating. A safety conclusion is not a comedogenicity finding and we do not use it as one.
  5. Draelos ZD, DiNardo JC. "A re-evaluation of the comedogenicity concept." J Am Acad Dermatol 54(3):507-512 (2006) A "Current Issues and Opinion" piece in JAAD that tested finished products on human upper backs in small panels. Cited only in the limits section, for the general point that an isolated ingredient's assay grade does not transfer to the formula it ends up in. It is not a same-substance rabbit-versus-human validation, it makes no measurement of Polysorbate 20, and we do not present it as either.
  6. "Comedogenicity in cosmeceuticals - a review of clinical relevance, regulatory gaps, and future directions." JAAD Reviews (2025) A recent peer-reviewed review of the whole field, covering literature from 1972 onward. It is a synthesis of the legacy literature rather than a new measurement, and independent of Fulton only in authorship, since the corpus it surveys includes him. Cited for the field-wide caveat that no standardised comedogenicity test exists and that "non-comedogenic" is an unregulated label.
  7. SpecialChem - Polysorbate 20, INCI ingredient reference A cosmetic-ingredient reference used here only for identity and function: that Polysorbate 20 is polyoxyethylene (20) sorbitan monolaurate, CAS 9005-64-5, sold as Tween 20, a nonionic emulsifier and surfactant. It is a formulation reference, not a study, and it makes no comedogenicity measurement. Disclosed because it also states flatly that the ingredient is "non-comedogenic" with no citation behind it, which is exactly the kind of sourceless assertion this page exists to separate from the two readings above.

Others in the same family

Emulsifiers behave similarly enough that the evidence for one is often wrongly read across to the others. These are its structural relatives, not a guess. What the evidence says about emulsifiers as a family ›

Last reviewed 2026-08-20 · How we decide

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