Corn Oil (Zea Mays)
Corn oil, which our list names Corn Oil (Zea Mays), is rated 3 on our list, in the moderate band, and the number is traced: Fulton 1989 graded it 3 and Morris and Kwan 1983 graded it 0 to 1.
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 corn oil comedogenic?
Corn Oil is rated 3 on the comedogenic scale, which is the moderate band.
An inexpensive, readily available vegetable oil used as a skin conditioning agent.
- Comedogenic rating
- 3 out of 5
- Band
- Moderate: Borderline plugging in the rabbit-ear test. Worth a look in a leave-on product.
- Where the number comes from
- Traced to Fulton 1989 and Morris and Kwan 1983. The section on who rated it prints each grade.
- Composition
- Natural Oil / Vegetable Oils
- Also written as
- No common variants recorded
What a 3 means in practice
Three is the middle of the scale. Fulton 1989 counted 2 to 3 as borderline in the rabbit-ear test: some plugging of the follicles, short of a clear positive. Whether it matters depends on how high it sits on the label and whether the product stays on your skin.
Two things change what this number is worth. Ingredients are listed in descending order of concentration, so corn oil near the top of a label matters far more than corn oil 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 corn oil 3. 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 3 | Tested as Corn oil |
| Morris and Kwan 1983 | Grade 0 to 1 | Tested as Corn Oil |
Ahn and colleagues 1985 reports moderate to severe comedogenicity in the rabbit ear canal, in an abstract that gives no 0 to 5 grade.
Our list's figure is within what these papers report.
Similar names, rated separately
These share a source with corn oil or carry it in their name, and each has its own rating on our list. The 3 on this page does not carry over to them, so check the exact name on the label.
Fungal acne
Corn Oil matches rule 4, plant or animal oil or butter , on the fungal acne checker. A plant or animal oil, mostly triglycerides. The rule comes from lab studies of what Malassezia yeast can feed on, and it is not a verdict on any product.
Common questions
- Is corn oil comedogenic?
- Corn Oil is rated 3 on the comedogenic scale, which is the moderate band.
- Is corn oil non comedogenic?
- No. Corn Oil is rated 3 on the comedogenic scale, which is the moderate band. That is a published rating for the ingredient rather than a verdict on any product containing it.
- What is corn oil's comedogenic rating?
- 3 out of 5 on our list. It is classed as Natural Oil / Vegetable Oils.
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.
- Morris WE, Kwan SC. “Use of the rabbit ear model in evaluating the comedogenic potential of cosmetic ingredients.” Journal of the Society of Cosmetic Chemists, August 1983;34(5):215–225. (opens in a new tab) Rabbit ear canal, at the Revlon Research Center. Each material applied undiluted unless stated, once a day five days a week for 14 applications, and graded 0 to 5 by microscope only. The authors set out to recheck earlier results because investigators disagreed.
- Ahn HY, Myung KB, Hahm JH, Kook HI. “An experimental study on comedogenicity of several external contactants.” Korean Journal of Dermatology, October 1985;23(5):620–629. (opens in a new tab) Rabbit ear canal; in the abstract’s words, the materials were applied to one ear canal of rabbits "for 6 weekdays for 2 weeks". Read at abstract level: the full text is not online. The abstract sorts ingredients into none, mild, moderate and severe with no 0 to 5 grade, and lists propylene glycol under both none and moderate. Kligman 1996 says that putting test materials inside the ear canal gave false positives in his own 1972 study, because loose horny material collects in the follicles there.
- 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.”