PPG-5 Ceteth-10 Phosphate
PPG-5-Ceteth-10 Phosphate is one of the ingredients whose circulating comedogenic number rests on a direct ingredient-name match: Fulton's 1989 rabbit-ear assay scored it 4 on his 0-to-5 scale. It is not a wrong-molecule score borrowed from a neighbour — but it is one three-rabbit experiment in one laboratory, and we identified no other measurement and no human test.
Ethoxylated/propoxylated phosphate emulsifier with a high legacy clog score.
What it is
PPG-5-Ceteth-10 Phosphate is a phosphate-ester emulsifier and surfactant. It is built from cetyl alcohol — the sixteen-carbon fatty alcohol — which is first alkoxylated (roughly five propylene-oxide units and about ten ethylene-oxide units are added, which is what the "PPG-5" and "Ceteth-10" in the name record) and then esterified with a phosphorus reagent to give the phosphate. Directory and supplier descriptions characterise it as a complex mixture of phosphoric-acid esters of the polyoxypropylene, polyoxyethylene ether of cetyl alcohol. Its job in a formula is to pull an oil phase and a water phase together and hold them there; it is also used as a solubiliser, a co-emulsifier and a texture agent, and it doubles as a mild cleansing surfactant. It is sold under trade names including Croda's Crodafos SG and Crodafos C10/5A and Elé Corporation's PEL-PHOS SG. On a label it appears as PPG-5-Ceteth-10 Phosphate. Keep the phosphate and the alkoxylation in view, because the name invites two confusions. It is not the same ingredient as Potassium Cetyl Phosphate, a different cetyl phosphate that directories list as its nearest alternative; and it is not one of the plain ethoxylated ethers (the laureths, oleths and steareths) whose scores this site treats as a series. It is a mixed propoxylated/ethoxylated cetyl chain carrying a phosphate head, and no other row in the primary table carries its name.
Why we rate it Clogging
We rate it Clogging, at Low confidence, and this page is the same shape as the oleth-3 page: the number is real. Most of the comedogenic scores this site takes apart turn out to belong to a different material — a neighbouring row, a derivative, a dropped word. This one does not. Fulton's 1989 survey in the Journal of the Society of Cosmetic Chemists — the source of nearly every comedogenic number in circulation — prints "PPG 5 Ceteth 10 phosphate" at 4, which is a direct ingredient-name match for this material rather than a score borrowed from a relative. We read the row off a transcription of Table I made visually from the journal scan, rather than off a chart quoting it, and the name is unambiguous: the entry sits among the paper's surfactant and ether rows. It is a match of names, and that is as far as it goes — Fulton records no supplier, no ester distribution and no neutralisation state for the sample he tested. It is worth saying what a 4 is in Fulton's own words, because the charts that republish his numbers drop his key: "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." So a 4 is inside the band Fulton called positive — not a borderline 2 or 3, and one step below the top of his scale, which he anchored to isopropyl myristate. The row also carries no asterisk. Fulton's asterisk — "results depend on source of raw material" — hangs off his oils-and-butters section, and this ingredient is not in it; it is a manufactured surfactant, and the 4 is printed without that raw-material caveat. One thing the table does not give us here is a series to read the 4 into, and it is worth being honest that it does not. The plain oleth and laureth rows fall as the molecule is ethoxylated further (Oleth-3 at 5 down to Oleth-20 at 1), which is a pattern printed in those rows. But the other alkoxylated cetyl and phosphate entries near this one do not line up: Oleth-3 phosphate is 2, PPG-10 cetyl ether is 3, and PPG-30 and PPG-50 cetyl esters are both 0. Those are different molecules, not a dose ladder for this one, and there is no clean trend to explain this 4 by. So we report it as what it is — a single measured row under this ingredient's own name — and we do not build a mechanism around it.
What the evidence doesn’t tell you
Everything behind the number happened inside the ear of a rabbit. The rabbit-ear assay, stated plainly: the ingredient at roughly 10% in propylene glycol, about 1 ml applied to the inner ear of New Zealand albino rabbits, three rabbits per assay, five days a week for two weeks, follicles then scored for keratosis under a micrometer. That is not a human face and not a finished formula, and we hold no measured in-use concentration for this ingredient to set the assay's roughly 10% against. We identified no human comedogenicity study of PPG-5-Ceteth-10 Phosphate in the papers we hold or the searches we ran — none on a face, none on a back, none with a comedone count. And the reading is one three-rabbit experiment in one laboratory. This is where PPG-5-Ceteth-10 Phosphate is thinner than an ingredient like laureth-4, whose legacy score Fulton recorded in two separate papers — though those two readings differ from each other, 5 in 1989 and 4 in 1984. We hold Fulton's earlier 1984 rabbit-ear table in full, and it has no PPG-5-Ceteth-10 phosphate row at all — the entry appears only in the 1989 survey. So we have no second Fulton reading of this material to compare against; Morris and Kwan, whose 1983 assay ran on the same 0-to-5 scale and who were willing to contradict Fulton in print, have no row for it either, and Nguyen, Dang and Maibach's 2007 rabbit study does not list it among its test materials. Those three absences are verified against the papers themselves. We identified no non-Fulton measurement of this ingredient's comedogenicity. The 4 is a single reading, by a single investigator, on a single model, and it is the whole of the numeric record we could trace. There is a claim pointing the other way that a reader will meet, and it should be named rather than quietly used. Ingredient directories and supplier-adjacent pages describe PPG-5-Ceteth-10 Phosphate as "non-comedogenic" within recommended concentrations. We could find no study, assay or measurement attached to that description — it is an unsourced assertion of the kind this site exists to flag, and we are not going to treat it as evidence in either direction. It is not a reason to lower the rating, and it is not a fabricated positive we are adopting; it is a marketing sentence with nothing behind it that we could read. Equally, we did not find a human study establishing that it is comedogenic in use, and we are not going to imply the rabbit 4 proves that it is. A note on where the safety literature sits, so a reader does not mistake it for a comedogenicity answer. Phosphate-ester surfactants of this class fall within the Cosmetic Ingredient Review's work on alkyl phosphates; we were unable to open that report's full text to confirm whether this exact ingredient is one of the materials it assessed, so we make no claim about what it concluded and cite it for nothing here. Even where such a review does cover an ingredient, it assesses safety — irritation, sensitisation, systemic toxicity — which is a different question from whether a material plugs a follicle. Finally, the field-wide caveat that sits under every legacy score on this site. The rabbit-ear model has been questioned since Frank's 1982 paper, and a 2025 review in JAAD Reviews, surveying the literature from 1972 onward, found that no standardised comedogenicity test exists and that "non-comedogenic" is an unregulated label. That is a remark about the standards of this whole subject, and it applies to PPG-5-Ceteth-10 Phosphate's 4 exactly as it applies to everyone's numbers. Fulton himself called his survey "not at all definitive but simply designed to stimulate research."
Where you’ll see it
On a label it is PPG-5-Ceteth-10 Phosphate. Ingredient directories and supplier listings record it as an emulsifying, surfactant and cleansing agent, and in practice it turns up as the emulsifier or co-emulsifier in creams, lotions, serums, cleansers, makeup removers, sunscreens, shampoos and conditioners — for example in a mineral sunscreen base (COVASCREEN ZN) and in conditioning shampoo formulations. Those are illustrative categories drawn from product and formulation listings, not a measured prevalence — we have not audited the market — and we are not going to tell you where it sits on an ingredient list, because label position is not a dose. Its trade names are worth knowing, because the same material appears under several: Crodafos SG and Crodafos C10/5A from Croda, and PEL-PHOS SG from Elé Corporation. Two neighbours are easy to confuse with it and are separate ingredients: Potassium Cetyl Phosphate, which directories list as its nearest alternative, and the plain ethoxylated ethers (laureths, oleths, steareths), which carry their own separate scores.
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 primary source of our legacy score and of nearly every comedogenic number in circulation. Method: the ingredient at roughly 10% in propylene glycol, about 1 ml applied to the inner ear of New Zealand albino rabbits, three rabbits per assay, five days a week for two weeks, follicles scored for keratosis on a 0–5 scale. Read off a visual transcription of Table I, not off a chart quoting it. It prints "PPG 5 Ceteth 10 phosphate" at 4 — a direct ingredient-name match, with no supplier, ester distribution or neutralisation state recorded, and with no raw-material asterisk (that asterisk hangs off the oils section, which this ingredient is not in). It supplies the grade key the charts omit ("0 to 1 not significant, 2 to 3 borderline, 4 to 5 positive"), so a 4 is inside Fulton's "positive" band. A rabbit-ear assay, and the author himself called the survey "not at all definitive but simply designed to stimulate research."
- 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) Fulton's earlier rabbit-ear paper, on the same 0–5 scale. Cited here for what it does NOT contain: it has no PPG-5-Ceteth-10 phosphate row at all — the entry appears only in the 1989 survey — which is why this page can say the 4 rests on one experiment. We hold its Table I in full, so the absence is verified, not assumed. It is the reason this ingredient's number is thinner than laureth-4's, which Fulton recorded in both papers, at 5 in 1989 and 4 in 1984.
- "Comedogenicity in cosmeceuticals: a review of clinical relevance, regulatory gaps, and future directions." JAAD Reviews (2025) Recent peer-reviewed review of the whole field, covering the literature from 1972 onward, and independent of Fulton and of the charts that republish him. Finds that no standardised comedogenicity test exists and that "non-comedogenic" is an unregulated label. Cited for the field-wide caveat that sits under every legacy score on this site, this ingredient's 4 included.
- SpecialChem — "PPG-5-Ceteth-10 Phosphate", cosmetics INCI directory entry (updated 6 November 2025) A cosmetics ingredient-directory entry, not a study — cited for what it actually documents: what the material is (a phosphate ester of the propoxylated/ethoxylated ether of cetyl alcohol; CosIng ref 78588), how it is made, its trade names (Crodafos SG, Crodafos C10/5A, PEL-PHOS SG) and the product categories it appears in. It also carries an uncited "non-irritating, non-sensitizing, and non-comedogenic" safety line with no study attached; that claim is named on this page as an example of a sourceless assertion and is used as evidence for nothing.
Others in the same family
Ethoxylates (PEGs & polysorbates) 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 ethoxylates (pegs & polysorbates) as a family ›
Last reviewed 2026-08-12 · How we decide