Porecelain

Flawless skin starts with the fine print.

Sorbitan Oleate

Sorbitan oleate is one of the few ingredients on this site whose circulating number was measured on the material named: Fulton's 1989 rabbit-ear survey has a row reading "Sorbitan oleate — 3" on a 0 to 5 scale. What the lists leave out is Fulton's own key, printed in the same paper, which calls a grade of 2 to 3 borderline and reserves "considered positive" for 4 to 5. We rate it Caution, which is what a borderline reading from one 1989 rabbit assay is worth.

Caution Low confidence Legacy score 3 on a 0-5 scale · Fulton 1989 · low reliability

Fulton 1989 rabbit ear 3 of 5 — borderline under his own key, not positive. One reading.

What it is

A nonionic emulsifier, sold for decades under the trade name Span 80. The Cosmetic Ingredient Review defines it as "the monoester of oleic acid and hexitol anhydrides derived from sorbitol" and gives two CAS numbers for it, 1338-43-8 and 37318-79-9. In plain terms: sorbitol, dehydrated into a ring called sorbitan, with a single oleic-acid chain — the C18:1 fatty acid — attached to it. CIR's properties table describes the commercial material as an amber, oily, viscous liquid of molecular weight 428.61 Da, insoluble in water and miscible with mineral and vegetable oils. That solubility is what it is for: it works on the oil side of an emulsion, and it is usually paired with a water-loving emulsifier rather than used alone. One qualification about what the name covers, because it matters to how a 1989 score should be read. The INCI definition names a monoester, but CIR's chemistry section describes this class as a whole in looser terms: "The sorbitan esters are mono-, di-, and triesters, and mixtures thereof, of fatty acids and 1,4-sorbitan," and it notes that some of the six-membered pyranyl ring form "may also be present," alongside impurities including free acid or alcohol and water. So the label name specifies a target structure. It does not by itself tell you the ester distribution in any particular drum. Three neighbours share the oleic-acid tail and are separate ingredients with separate entries here. SORBITAN SESQUIOLEATE is "a mixture of mono- and diesters of oleic acid" (CAS 8007-43-0) — a modern INCI name, and not the spelling Fulton's 1989 table prints. SORBITAN TRIOLEATE is the triester. And POLYSORBATE 80 is this molecule with roughly twenty ethylene-oxide units added — the ethoxylated derivative, not the same material. All four are declared separately on a label, and, as the next section sets out, they do not carry the same number.

Why we rate it Caution

We rate it Caution, at Low confidence. There is one numeric result for this material, it is a rabbit-ear reading from 1989, and reading it correctly is most of what this page has to offer. The number, and where it comes from. James Fulton's 1989 survey in the Journal of the Society of Cosmetic Chemists is the source of nearly every comedogenic score in circulation. His method: roughly 10% of the ingredient in propylene glycol, applied to the inner ear of New Zealand albino rabbits, three rabbits per assay, five days a week for two weeks, the follicles then read for keratosis under a micrometer. Read off the table itself rather than off a list quoting it, the row labelled "Sorbitan oleate" reads 3, on a 0 to 5 scale. It carries no asterisk, and it is not one of the rows in the paper's section VI, "Oils*" — the section whose heading footnote reads "Results depend on source of raw material" — so that particular caveat does not ride on this number. Material identity, which is usually where these pages turn. Most of the notorious scores on this site belong to a material sitting next to the one on the label: a butter read as an oil, a derivative read as its parent. This is not one of those. Fulton has a row for this exact name, and the 3 that the consumer databases print is the number on it. What an exact name match does not establish is sample identity. Fulton reports no supplier, no trade name, no grade, no ester distribution and no certificate of analysis for any row, so the material behind his "Sorbitan oleate" is not recoverable, and the CIR text above says the commercial class is compositionally looser than the INCI definition suggests. What the lists leave out, and the reason for this page. A 3 is routinely reported as "moderately comedogenic." Fulton's own grade key, printed in his methods on page 322 and quoted by almost nobody, says something else: "As reported in our previous studies, a minimal grade of 0 to 1 is not considered significant. Grade 2 to 3 is borderline. However, a grade of 4 to 5 is uniformally reproduceable and considered positive." By the key the author of the number published alongside it, a 3 sits at the top of the borderline band and below the threshold he was prepared to call positive. That cuts both ways, and we are not going to pretend otherwise: borderline is not a clean bill either. It is the middle of the scale, and Caution is the word this site uses for the middle of the scale. That is where the rating comes from — the 3 Fulton printed, read under the key Fulton published beside it, and nothing else. The rest of the family, in the same table. Fulton scored sorbitan stearate 0, sorbitan laurate 1–2*, sorbitan isostearate 1–2*, and a row he printed as "Sorbitan sesquinoleate" 0–1*. That spelling is his. Whether the row is the material now declared as Sorbitan Sesquioleate is not established, so we attribute the 0–1* to the row as printed and no further. Against those rows this one is the high reading of the group, which is a fact about one laboratory's ingredient set, read once, and not what the rating rests on. It is not a demonstrated mechanism either, and we are not going to build one out of adjacent rows: the sesquinoleate row carries the same oleic-acid tail in its printed name and reads 0–1*, and Polysorbate 80, this molecule ethoxylated, reads 0. Anyone tempted to conclude that the oleate chain is the problem, or that ethoxylation fixes it, should note that Fulton's own 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 (laneth 10)." We report the numbers and decline the story. A note on the citation trail, since three of these ingredients are one keystroke apart. The 3 in the consumer databases matches Fulton's row exactly, and Fulton's row is the only measurement of this material we have found. We did not trace who copied whom, and we are not going to assert a chain we did not follow. What we will say is narrower and checkable: the only sesqui- row in the 1989 table is the one printed "Sorbitan sesquinoleate" at 0–1*, so a comedogenic 3 attached to Sorbitan Sesquioleate traces to nothing in Fulton — and neither, strictly, does the 0–1*, because we have not established that his row and that ingredient are the same material.

What the evidence doesn’t tell you

One reading, one laboratory, one decade. We identified no second numeric assay of sorbitan oleate. Morris and Kwan's 1983 rabbit study — the contemporary paper that openly contradicts Fulton on several materials and says so in print — prints 32 rows, and none of them is a sorbitan ester under that name. The nearest is a row for "Polysorbate 20 (1% Aqueous)", which they scored 0 on their 0-to-5 scale: an ethoxylated sorbitan ester, and a different material from this one. Fulton, Pay and Fulton's 1984 paper, whose Table I we have read in full, has no sorbitan oleate row. Nguyen, Dang and Maibach's 2007 rabbit study names fourteen materials in its abstract and this is not one of them. So we identified no reading of it from a second laboratory, and there is nothing for us to weigh it against. We identified no human comedogenicity study of sorbitan oleate. We also identified no dose-response data for it: Fulton's general method describes roughly 10% in propylene glycol, while CIR's 2014 industry survey reports cosmetic use at up to 3% in leave-on products and up to 7% in rinse-off ones. Whether the reading holds, falls or disappears at those concentrations is not something any document we hold answers. The safety review is not a comedogenicity finding, and it is worth saying exactly what it does and does not contain. CIR's 2019 assessment of twenty sorbitan esters concluded they "are safe in cosmetics in the present practices of use and concentration." That is a safety conclusion, and safety is a different question from follicular plugging. The document mentions comedones exactly once in its whole length, and the sentence belongs to a different ester: of sorbitan isostearate and sorbitan sesquiisostearate it reports that "in other studies, the ingredient did not produce significant irritation, sensitization, or comedone formation." There is no comedogenicity result for sorbitan oleate in it. On sorbitan oleate itself it reports irritation only — undiluted material was "minimally irritating to rabbit skin when applied for 24 hours," and up to 100% applied for 30 days "produced no visible changes at 3 days but erythema and edema after 10 days." Irritation is not comedogenicity, and we are not using it as either evidence for or against the rating. We cannot reconstruct the test article, and that limit is larger than it looks. CIR's properties table lists sorbitan oleate as insoluble in propylene glycol — the vehicle Fulton's general method describes — and Fulton reports no per-row vehicle, concentration or supplier. So whether his sample was in solution or dispersed is not recoverable from the paper. This is not an argument that the 3 is too high or too low; it is an argument that we do not know what was on the ear. The same caveat applies to other rows in the group (sorbitan laurate is listed insoluble in propylene glycol too), so it is not special pleading for this one number. The argument we are declining to make. Free oleic acid has a reputation in this literature, and it would be easy to lend it to an ester of oleic acid. Kanaar's 1971 study of the rabbit external ear canal reports that "laurinic acid and oleic acid induced marked ... inflammation and follicular keratosis." That is a different material — a free fatty acid, not a fatty acid esterified to a sorbitan ring — tested at a different site, and graded in words rather than on any numeric scale. Transferring it here would be the exact substitution this site exists to catch, so we note it and stop. And the model itself. Everything above rests on a rabbit's ear. Draelos and DiNardo's 2006 re-evaluation, a "Current Issues & Opinion" piece that tested finished products on small human panels, argued that isolated rabbit-ear ingredient scores are a poor guide to what a product does on a human face; a 2025 review in JAAD Reviews found that no standardised comedogenicity test exists and that "non-comedogenic" is an unregulated label. Fulton himself wrote that his survey was "not at all definitive but simply designed to stimulate research." Those objections apply to this 3 as much as to anybody's 0.

Where you’ll see it

On a label it reads Sorbitan Oleate; in supplier documents and older literature it is Span 80. CIR reports 311 uses in the FDA's 2014 Voluntary Cosmetic Registration Program data — 205 leave-on, 106 rinse-off — at survey concentrations from 0.0025% to 7%. That is voluntary industry reporting rather than a market audit we have run, and it is the only use figure we are prepared to give: we have not counted products, and label position is not a dose. Three near neighbours are rated separately and should not be read off this page: Sorbitan Sesquioleate, the mono- and diester mixture; Sorbitan Trioleate; and Polysorbate 80, the ethoxylated version, which Fulton scored 0. Fulton's table also carries a row printed "Sorbitan sesquinoleate" at 0–1*, and whether that row is the modern Sorbitan Sesquioleate is not established here. One word on the label decides which of them you are holding.

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) The primary source of nearly every comedogenic score online, and the only numeric assay of sorbitan oleate we have found. Read off a render of the journal scan rather than from a list quoting it. Method: ingredient at roughly 10% in propylene glycol, applied to the inner ear of New Zealand albino rabbits five days a week for two weeks, three rabbits per assay, follicles then read for keratosis. Its "Sorbitan oleate" row reads 3, with no asterisk and outside the asterisked oils section; the same table reads sorbitan stearate 0, sorbitan laurate 1–2*, sorbitan isostearate 1–2*, Polysorbate 80 at 0, and a row printed "Sorbitan sesquinoleate" at 0–1* — a spelling we have not matched to a modern INCI name. Cited here as much for its grade key as for its number: Fulton's methods define 0 to 1 as "not considered significant," 2 to 3 as "borderline" and 4 to 5 as "considered positive," and he called the whole survey "not at all definitive." It reports no supplier, grade or composition for any row, so it establishes a reading on a material Fulton called sorbitan oleate, not on a characterised sample.
  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, on the same 0 to 5 scale, which contradicts him on several materials and says so in print — so it is a genuine independent check where it overlaps. Cited here for what it does NOT contain: its 32 rows (seven lanolins, nine vegetable oils, eleven esters, five surfactants) include no sorbitan ester under that name, the nearest being "Polysorbate 20 (1% Aqueous)" at 0 on their scale, an ethoxylated sorbitan ester rather than this one. We identified no second reading of sorbitan oleate to test Fulton's 3 against.
  3. Fulton JE, Pay SR, Fulton JE III. "Comedogenicity of current therapeutic products, cosmetics, and ingredients in the rabbit ear." J Am Acad Dermatol 10(1):96–105 (1984) The same author's earlier rabbit-ear paper, read in full from a print copy rather than from its abstract. Cited only to close off an absence: its Table I contains no sorbitan oleate row, so it adds no earlier reading. Worth knowing that its grade key differs from the 1989 one — in 1984, "a grading score of 3 or above is uniformly reproducible and considered positive," where 1989 calls 3 borderline — which is why a number from one paper may never be read under the other's key.
  4. Nguyen SH, Dang TP, Maibach HI. "Comedogenicity in rabbit: some cosmetic ingredients/vehicles." Cutan Ocul Toxicol 26(4):287–292 (2007) A later rabbit-ear study on a 0 to 4 scale, of which we have read the abstract verbatim and not the full text. Cited only for its inventory: the fourteen materials it names are esters, butters, fatty alcohols, paraffin, sodium lauryl sulfate and petrolatum, and sorbitan oleate is not among them. It contributes no number here, and we carry none from it.
  5. Fiume MM, Bergfeld WF, Belsito DV, Hill RA, Klaassen CD, Liebler DC, Marks JG, Shank RC, Slaga TJ, Snyder PW, Gill LJ, Heldreth B. "Safety Assessment of Sorbitan Esters as Used in Cosmetics." Int J Toxicol 38(2_suppl):60S–80S (2019) The final published expert-panel review of twenty sorbitan esters, in the peer-reviewed literature rather than one of CIR's draft, tentative or re-review packets — we read the published article, not a comment-stage PDF. It is a SAFETY assessment, and we use it only for identity, composition and use: the INCI definition and CAS numbers, the molecular weight and solubility, the statement that the class comprises "mono-, di-, and triesters, and mixtures thereof," and the 2014 use and concentration figures. It contains no comedogenicity result for sorbitan oleate. Its single mention of comedones concerns sorbitan isostearate and sorbitan sesquiisostearate, a different ester, and its conclusion that these ingredients "are safe in cosmetics in the present practices of use and concentration" is not a finding about follicular plugging. Its use figures come from voluntary industry reporting (the FDA's VCRP and a Personal Care Products Council survey), not from an independent market audit.
  6. Kanaar P. "Follicular-keratogenic properties of fatty acids in the external ear canal of the rabbit." Dermatologica 142(1):14–22 (1971) Cited here to be set aside, not used. We have read its abstract verbatim, not the full text. It tested FREE FATTY ACIDS — not esters of them — in the rabbit external ear CANAL rather than on the ear surface, and it grades in words rather than numbers, so no score can be derived from it at all. Its finding that oleic acid "induced marked ... inflammation and follicular keratosis" is about a different material at a different site, and transferring it to a sorbitan ester of oleic acid would be an inference, not a result.
  7. Draelos ZD, DiNardo JC. "A re-evaluation of the comedogenicity concept." J Am Acad Dermatol 54:507–512 (2006) A "Current Issues & Opinion" piece, not a controlled trial: it tested FINISHED PRODUCTS on small human panels and argued that isolated rabbit-ear ingredient scores are a poor guide to what a product does on human skin. It did not test sorbitan oleate, and it is not a rabbit-versus-human validation of any single material. Cited because it undercuts this page's 3 exactly as hard as it undercuts anyone's 0.
  8. CosDNA — Sorbitan Oleate ingredient entry A consumer ingredient database, not a measurement, cited for disclosure: it is one of the places a reader will already have met an acne rating of 3 for this ingredient. Its number matches Fulton's row. That is consistency, not corroboration — it is a republished figure, and we did not trace the path it took to get there.

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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