Steareth-10
Steareth-10 is rated 4 on our list, in the high band, and the number is traced: Fulton 1989 graded it 4.
Like every rating here, it is for the raw ingredient tested alone, and a label does not print how much of it a product holds.
Is steareth-10 comedogenic?
Steareth-10 is rated 4 on the comedogenic scale, which is the high band.
A polyethylene glycol ether of stearic acid used to cleanse and emulsify formulas.
- Comedogenic rating
- 4 out of 5
- Band
- High: Clear plugging in the rabbit-ear test. The first band to check in a leave-on product.
- Where the number comes from
- Traced to Fulton 1989. The section on who rated it prints each grade.
- Composition
- Surfactant / Emulsifier / Alcohols & Derivatives
- Also written as
- No common variants recorded
What a 4 means in practice
A 4 or 5 is the top of the scale. In the rabbit-ear test, Fulton 1989 counted 4 to 5 as a clear positive: the ingredient plugged the follicles, and did so repeatably. A person's skin reacts less readily than a rabbit's ear, and a product holds far less of the ingredient than the test did, so treat this band as the first thing to check in anything that stays on your skin. It does not prove the ingredient will cause a breakout. A rinse-off product is on the skin for seconds.
Two things change what this number is worth. Ingredients are listed in descending order of concentration, so steareth-10 near the top of a label matters far more than steareth-10 at the bottom. And the rating describes the raw ingredient on its own. A 2006 review in the Journal of the American Academy of Dermatology found that a rating for a single ingredient does not reliably predict how a finished formula behaves on human skin. The full story of the scale is here.
Who rated it
Our list gives steareth-10 4. These are the figures the published rabbit-ear studies we have read give it, as printed in each paper's table.
| Paper | Grade | Tested as |
|---|---|---|
| Fulton 1989 | Grade 4 | Tested as Steareth-10 |
Our list's figure is within what these papers report.
Common questions
- Is steareth-10 comedogenic?
- Steareth-10 is rated 4 on the comedogenic scale, which is the high band.
- Is steareth-10 non comedogenic?
- No. Steareth-10 is rated 4 on the comedogenic scale, which is the high band. That is a published rating for the ingredient rather than a verdict on any product containing it.
- What is steareth-10's comedogenic rating?
- 4 out of 5 on our list. It is classed as Surfactant / Emulsifier / Alcohols & Derivatives.
Sources we checked this rating against
- Kligman AM, Kwong T. “An improved rabbit ear model for assessing comedogenic substances.” British Journal of Dermatology, June 1979;100(6):699–702. (opens in a new tab) The rabbit-ear assay behind published 0 to 5 comedogenicity grades.
- Fulton JE Jr. “Comedogenicity and irritancy of commonly used ingredients in skin care products.” Journal of the Society of Cosmetic Chemists, November/December 1989;40(6):321–333. (opens in a new tab) Rabbit ear. Each ingredient at 10 percent in propylene glycol unless stated, applied five days a week for two weeks, and graded 0 to 5 from the width of the follicles, measured by micrometer and under the microscope. The paper counts 0 to 1 as not significant, 2 to 3 as borderline and 4 to 5 as positive. Some grades depended on the supplier of the raw material, and some oils were also tested refined.
- Draelos ZD, DiNardo JC. “A re-evaluation of the comedogenicity concept.” Journal of the American Academy of Dermatology, March 2006;54(3):507–512. doi:10.1016/j.jaad.2005.11.1058 (opens in a new tab) Tested finished products on the backs of six people and concluded that “Finished products using comedogenic ingredients are not necessarily comedogenic.”