Sodium Chloride

Sodium chloride does not appear in any comedogenicity assay we have been able to find — not in Fulton's 220-row table, not in Morris and Kwan's, not in the seven other numeric documents we hold. The 5 out of 5 that circulates for it is not a measurement. It rates Clear on the absence of any evidence against it, which is a weaker and different thing than a test it passed.

What it is

Table salt. An inorganic salt, sodium and chloride. It is the same compound you keep in a grinder, though not the same specification: table salt commonly carries iodising and anti-caking agents that a cosmetic grade does not. The Personal Care Products Council's ingredient database lists its cosmetic functions as viscosity increasing agent (aqueous), oral care agent and flavouring agent, and records its use across oral hygiene, shampoo, fragrance, skin, hair, nail, cleansing, suntan, makeup and bath products. The function that matters most on a skincare label is the first one: in a water-based surfactant system, adding salt thickens the liquid. That is why it turns up near the end of the ingredient list of a great many cleansers and body washes, doing little you would notice and a great deal to the texture of the product in the bottle.

Why we rate it Clear

Start with what is missing, because on this ingredient the absence is the whole finding. Sodium chloride has no row in Fulton 1989. We hold a verbatim transcription of all 220 rows of his Table I, read visually off the journal scan, and salt is not among them. It is not in Table II or Table III either. Nor is potassium chloride. Fulton tested oils, esters, lanolins, ethoxylates, waxes, alcohols, pigments and finished products; he did not test the salt. Morris and Kwan 1983, the other 0-5 rabbit-ear paper and the earlier one, reports 32 rows — seven lanolins, nine vegetable oils, eleven esters, five surfactants — and salt is in none of them. We searched the remaining numeric documents we hold, and the published literature beyond them, and identified no comedogenicity assay of sodium chloride, in any species, on any scale, in either direction. So the 5 out of 5 is not a reading. The interesting question is where it came from, and here we have to stop short of the satisfying answer, because we could not establish one. What we can establish is that it is old. On 14 September 2005, a user of the acne.org forum asked: "How come sodium chloride (salt) has a comedogenic rating of 5 out of 5 (worst) and people say sea salt helps their acne?" Nobody in the thread could source the number either. One replied that the standard test was a swab on the inside of a white rabbit's ear, and asked whether our faces are really the same as the inside of a rabbit's ear — which is, twenty years early, the correct question. The number was already being handed around as received fact, by people who could not say where it had come from, two decades ago. We are in the same position they were, with more of the primary documents in hand and still no row to point at. It is worth naming what we are not doing. There is an obvious argument available — salt is freely water-soluble, it does not sit in a follicle as a grease does, therefore it cannot plug one — and it is the kind of argument this site exists to distrust. It is a mechanism, not a measurement, and reasoning from what a molecule ought to do is precisely how the lists we correct got their numbers. We rate sodium chloride Clear because nothing has ever been found against it, not because we have worked out that nothing could be.

What the evidence doesn’t tell you

Absence of evidence is a weaker thing than evidence of absence. No one has published a rabbit-ear assay of salt that we can find, and no one has published a human comedone count for it either. "No signal" and "nobody looked" produce the same silence, and this is the second kind. Clear is the least-wrong call available, not a clean bill of health, and if the assay were run tomorrow we would have no grounds to be surprised by the result in either direction. Our tracing of the 5 is incomplete, and we would rather say so than tidy it. We have dated it to at least September 2005 and found no primary document behind it. We have not identified who first printed it or what they thought they were reporting. It is fair to say we cannot trace the number to a measurement; it is not fair to say we know it was invented, and we do not know that. There is one human study connecting sodium chloride to acne, and it is easy to misuse, so here it is with its endpoint stated. El Darouti and colleagues (2016) compared 200 acne patients with 200 matched controls in Cairo and found the patients reported eating significantly more salt — a median 3367.54 mg of sodium chloride a day against 2271.80 mg, and earlier onset of acne at higher intakes. That is a dietary case-control study. Salt intake was estimated from a single 24-hour recall and a food-composition table, not measured; no one applied anything to anybody's skin; no one counted a comedone; and salty food travels with fried and processed food, so the exposure is confounded with the diet it sits in. It is a real result and it is about swallowing salt, not wearing it. It cannot tell you whether salt in a cleanser plugs a follicle, and we are not going to let it. Safety data is not comedogenicity data. The Cosmetic Ingredient Review has never assessed sodium chloride — it formally deferred, because the FDA had already reviewed the safety of the substance — so unlike shea butter, there is not even an industry dossier whose silence on comedones we can point to. That salt is Generally Recognised As Safe in food, and approved as an active in over-the-counter ophthalmic products at 2 to 5%, says nothing whatever about follicular keratosis. Finally, the clinical questions people actually arrive with — whether a coarse salt scrub irritates a face, whether sea-water helps or harms acne-prone skin — are not comedogenicity questions, and we have found no evidence that bears on them.

Where you’ll see it

Predominantly in water-based, surfactant-based products, where it adjusts viscosity: facial cleansers, body washes, shampoos. Also in bath salts and salt scrubs, where it is the abrasive rather than a trace additive, and in oral care. The PCPC's database records its use across oral hygiene, shampoo, fragrance, skin, hair, nail, cleansing, suntan, makeup and bath products.

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 rabbit-ear assay nearly every comedogenic score online descends from: test material at roughly 10% in propylene glycol, applied to the inner ear of three New Zealand albino rabbits, follicles scored 0–5 for keratosis. Fulton's own key reads 0–1 "not considered significant", 2–3 "borderline", 4–5 "considered positive". Cited here entirely for what it does not contain. We hold a verbatim transcription of all 220 rows of Table I, read visually at 400dpi off the journal scan because OCR drops the numeric columns, and there is no sodium chloride row in it — nor in Tables II and III, nor a potassium chloride row anywhere. Fulton called his own survey "not at all definitive but simply designed to stimulate research."
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) The other 0–5 rabbit-ear paper, and the earlier one — three rabbits, undiluted material unless stated, 14 applications, microscopic grading. It is not a republisher of Fulton; it openly contradicts him in print on sodium lauryl sulfate. It reports 32 rows: seven lanolins, nine vegetable oils, eleven esters, five surfactants. Cited here, again, for an absence — sodium chloride is not one of them. The two largest 0–5 assays in the literature both declined to test the most common inorganic salt on earth.
3. "Sodium chloride / Salt" — thread on the Acne.org forum, opened 14 September 2005 A consumer forum thread, and not evidence of anything about skin. Its entire value here is the date. It opens "How come sodium chloride (salt) has a comedogenic rating of 5 out of 5 (worst) and people say sea salt helps their acne?" — which establishes that the 5 was already in circulation, and already unsourceable by the people quoting it, in 2005. No participant could name a study. Cited as the earliest instance of the number we were able to find, and as evidence that our own tracing of it is incomplete rather than complete.
4. El Darouti MA, Zeid OA, Abdel Halim DM, Hegazy R, Kadry D, Shehab DI, Abdelhaliem HS, Saleh MA. "Salty and spicy food; are they involved in the pathogenesis of acne vulgaris? A case controlled study." J Cosmet Dermatol 15(2):145–149 (2016) The only human study we found linking sodium chloride to acne, and it is a DIETARY one. A case-control design: 200 acne patients and 200 age- and gender-matched controls at Cairo University, salt intake estimated by a single 24-hour dietary recall scored against a national food-composition table. Patients reported a median 3367.54 mg of NaCl a day against 2271.80 mg in controls (P < 0.001), with higher intake correlating with earlier onset (r = -0.216, P = 0.031) but not with duration or severity. The endpoint is self-reported diet versus the presence of acne. It counted no comedones, applied nothing to skin, and cannot be transposed onto a topical ingredient — salty food is also fried and processed food, and the study cannot separate them. Included because it is the study that most complicates this page, and leaving it out would make one-directional evidence look unanimous.
5. Cosmetics Info (Personal Care Products Council) — "Sodium Chloride" ingredient entry The cosmetics industry's own consumer-facing ingredient database, run by the trade association — so an interested party, and cited only for facts it is well placed to state. It gives the cosmetic functions (viscosity increasing agent — aqueous, oral care agent, flavouring agent) and the product categories. It also records that the Cosmetic Ingredient Review DEFERRED evaluation of sodium chloride because the FDA had assessed its safety — which is why no CIR dossier exists for salt. That is a statement about safety review, not about comedogenicity: the two are different questions and this document addresses only the first.
6. Face Reality Skincare — "Pore-Clogging Ingredients List" An acne clinic's avoid-list: roughly eighty ingredient names in two columns, with no method, no score, no patient count and no citation. It is an assertion, not a measurement, and it is one of the lists that drives this whole category of belief. Read in full on 13 July 2026, and cited for a genuine surprise: sodium chloride is NOT on it. Potassium chloride is. The clinic list that names shea butter, coconut oil and wheat germ oil as pore-clogging does not name table salt — so whatever the 5 in circulation is, it is not currently coming from here.
7. "Comedogenicity in cosmeceuticals: a review of clinical relevance, regulatory gaps, and future directions." JAAD Reviews (2025) A recent peer-reviewed review of the field, 1972 to 2025. It is a synthesis of the legacy literature, not a new measurement, and independent of Fulton only in authorship, since the corpus it surveys includes his. It finds that no standardised comedogenicity test exists and that "non-comedogenic" is an unregulated claim. Cited for context: a fifty-year literature with no agreed method can easily never have got round to testing an ingredient, while the consumer-facing charts derived from it print a number for everything regardless.

Others in the same family

Minerals & pigments 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 minerals & pigments as a family ›

• Bentonite Clear Low
• Iron Oxides Clear Low
• Kaolin Clear Low
• Talc Clear Low
• Titanium Dioxide Clear Low
• Zinc Oxide Clear Low

Last reviewed 2026-07-13 · How we decide

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