Triethanolamine
Triethanolamine is rated Caution, and the number attached to it in circulation is lower than the one measurement we can trace: Fulton's 1989 rabbit-ear table prints 2 of 5, which his own key files under "borderline" rather than insignificant, and borderline is what Caution means here. The entry one row below it in the same table — "Stearic acid: TEA" — is a cold-cream formulation experiment, not a second reading of the amine, and its number stays off this page.
Fulton 1989 scored 2 of 5 — borderline under his key, not the 0 or 1 the charts print.
What it is
Triethanolamine is a tertiary alkanolamine: an amine carrying three ethanol arms. The Cosmetic Ingredient Review's 2013 assessment reports it as functioning in cosmetics as "a surfactant or pH adjuster", and on most labels the second job is the real one. It is alkaline, so a formulator adds a little of it to bring an acidic formula up to a workable pH, or to neutralise a thickener such as a carbomer so that it gels. On a label it appears as Triethanolamine, sometimes abbreviated TEA. One thing it does is worth separating out now, because the evidence section turns on it. When triethanolamine is combined with a fatty acid, the two form a salt — a soap. The CIR report describes TEA-stearate being produced by "mixing partially neutralized stearic acid and TEA at temperatures above 80°C and then cooling", and, summarising an in vitro penetration study, notes that the authors "suggested that all the TEA in a TEA/stearic acid emulsion existed as the TEA stearate salt, since an excess of stearic acid was used." That is one study's emulsion, not a general law about every product. But it means the amine and the soap are two materials, and a label listing both triethanolamine and stearic acid does not tell you the proportions of either.
Why we rate it Caution
We rate triethanolamine Caution at Low confidence. The Low is the evidence: a single legacy rabbit-ear reading, from 1989, in an animal model. The Caution is the paper's own key — Fulton put a 2 in his borderline band, and borderline is what this site calls Caution. The reading sits below his threshold for a positive result, which is a different thing from sitting inside his not-significant band, and we are not going to move it there on his behalf. Fulton's 1989 survey — the table most circulating comedogenic numbers descend from — has a row for the exact material. It reads "Triethanolamine 2" on his 0–5 scale. We read it off a 400dpi render of the journal scan rather than from a list quoting it. There is no asterisk on the row, no range and no parenthesis, so none of Fulton's qualifiers apply to it. The method behind the number is the one behind every number in that table: the ingredient diluted to roughly 10% in propylene glycol, 1 mL applied to the inner ear of New Zealand albino rabbits, three rabbits per assay, five days a week for two weeks, the resulting follicular keratosis measured with a micrometer. The part almost nobody quotes is Fulton's own key to his own scale: "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 standard of the man who produced it, a 2 is borderline. It is not a finding of comedogenicity, and it is not a clean bill of health either. It is also higher than the number in circulation. The pages we found asserting a comedogenic figure for triethanolamine put it at 0 or 1 — commercial ingredient-description pages, none of which named a study, a table or a year. We could not reach CosDNA to see what it prints. So we cannot trace where the lower figure came from, and we are not going to guess; what we can say is that the one printed measurement we can point at reads 2, and that it is worse than what is being repeated about it rather than better. Two neighbouring rows have to be kept apart from this one, because the whole method of this site is refusing to let a score drift onto a material that did not earn it. Directly beneath triethanolamine in Fulton's table sits "Stearic acid: TEA" at 3 — and that row is not an isolated assay of the TEA-stearate soap. It reports a formulation experiment, in Fulton's words: "In testing different ratios [4:1, 1:1, 1:4] of stearic acid to triethanolamine (stearic acid:TEA) in a cold cream base, all combinations were found to be comedogenic." That is evidence about mixtures in a cold-cream base, and its 3 transfers neither to the amine nor to a defined TEA-stearate material. An earlier version of this page called that row the soap measured on its own; the emulsifier hub's external fact-check caught the error, and it is corrected here. Elsewhere in the same table, plain stearic acid reads 2–3*, the asterisk being Fulton's note that results depend on the source of the raw material. The 2 on this page belongs to triethanolamine alone.
What the evidence doesn’t tell you
The rating rests on one reading, in three rabbits, at one concentration, in 1989. 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 triethanolamine. There is no second assay in the corpus we searched to check the first against. Morris and Kwan's 1983 rabbit-ear study is the one legacy paper that openly contradicts Fulton in print, which makes it the natural place to look for corroboration — but its 32 test materials were seven lanolins, nine vegetable oils, eleven esters and five surfactants, and triethanolamine is not among them. Fulton's own 1984 paper carries no triethanolamine row either, and neither does Nguyen 2007. Those are absences we checked in the papers themselves. So the 2 has no independent corroboration in either direction. It is one measurement, not two that agree. There is a confound inside the number that a single score cannot resolve. The CIR reports that in its earlier 1983 assessment "data demonstrated that TEA was a mild skin and eye irritant and that irritation increased with increasing ingredient concentration." Fulton's endpoint is follicular keratosis, and Draelos and DiNardo's 2006 paper argues that rabbit-ear results do not reliably transfer to human skin — in part because the model responds to irritation. We cannot tell from a single graded figure how much of a borderline 2 is plugging and how much is irritation, and we are not going to assert an answer we do not have. The concentration gap is real, and it does not settle the question either. Fulton tested at roughly 10% in propylene glycol. The CIR's 2013 industry survey reports triethanolamine used at 0.0002% to 19% overall and 0.0002% to 6% in leave-on products, and the EU permits trialkanolamines at up to 2.5% in non-rinse-off products under conditions of purity. An assay concentration above the common leave-on range is worth knowing. But Fulton anticipated exactly this argument and rejected it in his own conclusion: "We are not convinced of the statement that lower concentrations of these compounds can be safely used with no comedogenic consequences." He was writing about his major offenders, not about this row. We cite it because the reassuring version of the dilution argument is one he declined to make, and it would be dishonest to make it for him. The CIR assessment is not evidence for this rating in either direction. It is a safety document: it addresses irritation, sensitisation, systemic toxicity and nitrosamine formation. We found no assessment of comedogenicity in it, and a safety conclusion is not a comedogenicity finding. The question triethanolamine is actually argued over — that as a tertiary amine it can undergo nitrosative cleavage and act as a precursor to N-nitrosodiethanolamine, which is why the CIR says it "should not be used in cosmetic products in which N-nitroso compounds can be formed" — is a different question from pores, and this page does not assess it. Finally, the ceiling over everything here. A 2025 review of the field reports that no standardised comedogenicity test exists and that "non-comedogenic" is an unregulated label. That applies to this page as much as to the ones we disagree with.
Where you’ll see it
Creams, lotions, cleansers, sunscreens and colour cosmetics, usually as the thing that sets the pH rather than as anything the reader is buying the product for. The CIR's 2013 report cites Voluntary Cosmetic Registration Program data from 2011 showing triethanolamine in 3756 formulations, 3034 of them leave-on, at reported leave-on concentrations of 0.0002% to 6%. On a label it often sits near stearic acid or a carbomer, which is a clue to what it is doing there.
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.
- Fulton JE. "Comedogenicity and irritancy of commonly used ingredients in skin care products." J Soc Cosmet Chem 40:321–333 (1989) The rabbit-ear survey most circulating comedogenic numbers descend from, and the only document we found that measured triethanolamine. Read here off a 400dpi render of the journal scan rather than through a list quoting it. Method: ingredient diluted to roughly 10% in propylene glycol, 1 mL to the inner ear of New Zealand albino rabbits, three rabbits per assay, five days a week for two weeks, follicular keratosis measured with a micrometer, graded 0–5. Table I prints "Triethanolamine 2" — the exact material, with no asterisk, no range and no parenthesis — and, as a separate row, "Stearic acid: TEA 3", an entry the paper's text ties to ratios of stearic acid and triethanolamine tested in a cold cream base: a formulation result, not an isolated reading of the salt, and not a second reading of the amine. Fulton's own key places 2 in the "borderline" band and reserves "considered positive" for 4 and 5. He called the survey "not at all definitive", and his conclusion declines the dilution defence: "We are not convinced of the statement that lower concentrations of these compounds can be safely used with no comedogenic consequences." One reading, one model, one concentration.
- 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) An independent laboratory's rabbit-ear assay on the same 0–5 scale, predating Fulton 1989 and contradicting it in print on several materials, which is why it is not simply a republisher of him. Its 32 test materials were seven lanolins, nine vegetable oils, eleven esters and five surfactants. Cited here for a bounded absence: triethanolamine is not among them, so it offers Fulton's 2 no corroboration and no contradiction.
- Fiume MM, Heldreth B, Bergfeld WF, et al. "Safety Assessment of Triethanolamine and Triethanolamine-Containing Ingredients as Used in Cosmetics." Int J Toxicol 32(3 Suppl):59S–83S (2013) The industry expert-panel SAFETY dossier for triethanolamine and 31 related ingredients, in its final published journal state — a research article first published online 21 May 2013, not a draft or tentative report for comment. Cited only for identity, use and one caveat: its statement that triethanolamine functions as "a surfactant or pH adjuster"; the 2011 VCRP figure of 3756 formulations and the industry survey range of 0.0002% to 19% overall and 0.0002% to 6% leave-on; the EU limit on trialkanolamines; the description of TEA-stearate as the salt of stearic acid and TEA; and the record that the Panel's 1983 assessment found TEA "a mild skin and eye irritant" whose irritation "increased with increasing ingredient concentration". It assesses safety, sensitisation, systemic toxicity and nitrosamine formation. We found no assessment of comedogenicity in it, and it is offered as evidence of none. Note that the copy we read was retrieved online and its later sections were truncated in retrieval, so our statement about what it does not contain is bounded to what we read.
- 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, not a controlled same-substance validation of the rabbit ear against human skin: its own testing was of finished products on small upper-back panels. It argues that rabbit-ear results do not reliably predict comedogenicity in human skin and that testing an isolated ingredient says little about a finished formula. Cited against this rating as much as for it — it is a large part of why the confidence here stays Low on a borderline score.
- "Comedogenicity in cosmeceuticals: a review of clinical relevance, regulatory gaps, and future directions." JAAD Reviews (2025) A recent peer-reviewed review of the comedogenicity field covering literature from 1972 onward. A synthesis of the same legacy corpus, not a new measurement, and independent of Fulton only in authorship. Cited for one field-wide caveat: no standardised comedogenicity test exists, and "non-comedogenic" is an unregulated label.
- Commercial ingredient-description pages asserting a comedogenic figure for triethanolamine Supplier blogs and ingredient-glossary pages that state a comedogenic rating of 0 or 1 for triethanolamine. Not sources in any useful sense: none we read named a study, a table, an author or a year, and several were plainly machine-generated. Cited only to record what a reader searching this ingredient will actually be told, and to mark the distance between that figure and the one printed measurement we can trace. We were unable to retrieve CosDNA to establish what it publishes for this ingredient, so we make no claim about it.
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 2026-08-12 · How we decide