Is PEG-40 hydrogenated castor oil non comedogenic?

Not exactly. PEG-40 Hydrogenated Castor Oil is rated 2, which is the low band rather than 0. Low and non-comedogenic are different things, and only a 0 means the second one.

What is PEG-40 hydrogenated castor oil's comedogenic rating?

2 out of 5 on our list. It is classed as Oils. We have not found a published study that grades it, so treat this number as unconfirmed.

PEG-40 Hydrogenated Castor Oil

This is a castor oil derivative, rated separately. Plain castor oil: castor oil. Every castor oil entry is on one table with its rating.

PEG-40 hydrogenated castor oil (INCI name PEG-40 Hydrogenated Castor Oil) is rated 2 on our list, in the low band, and that number is unconfirmed: we have not traced it to a published study (what unconfirmed means).

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 PEG-40 hydrogenated castor oil comedogenic?

2 Low unconfirmed

PEG-40 Hydrogenated Castor Oil is rated 2 on the comedogenic scale, which is the low band.

Used predominantly to dissolve essential oils and fragrances into water without turning cloudy.

Comedogenic rating: 2 out of 5
Band: Low: Little plugging in the rabbit-ear test. Fulton 1989 counts 0 to 1 as not significant and 2 as borderline.
Where the number comes from: Unconfirmed. We could not trace this rating to a study we have read; the section on who rated it says what we checked.
Composition: Oils
Also written as: No common variants recorded

Where PEG-40 Hydrogenated Castor Oil sits on the 0 to 5 comedogenic scale. A single rating on our list, so the scale carries one mark. The papers we checked it against are under Sources we checked this rating against further down this page.

What a 2 means in practice

One and two are the low band. In the rabbit-ear test, Fulton 1989 counted 0 to 1 as not significant and 2 as borderline. A low grade on a rabbit's ear, which reacts more readily than human skin, is weak evidence of a problem on a person.

Two things change what this number is worth. Ingredients are listed in descending order of concentration, so peg-40 hydrogenated castor oil near the top of a label matters far more than peg-40 hydrogenated castor 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.

Check a whole ingredient list

Who rated it

We could not trace the 2 on our list to a paper we have read. Neither paper we could read tests PEG-40 hydrogenated castor oil. Fulton 1989 rates PEG 40 castor oil, which is not hydrogenated. The list does not say where its numbers came from, so treat this number as unconfirmed rather than as one we can tie to a table.

A grade is for the raw ingredient tested alone on a rabbit's ear, which reacts more readily than human skin. It says nothing about how much of it a product holds or what the rest of the formula does.

Similar names, rated separately

These share a source with peg-40 hydrogenated castor oil or carry it in their name, and each has its own rating on our list. The 2 on this page does not carry over to them, so check the exact name on the label.

Others in the same family

Oils · 62 ingredients on this list

Fungal acne

PEG-40 Hydrogenated Castor Oil matches rule 2, ester of a C12 to C24 fatty acid , on the fungal acne checker. An ethoxylated castor oil. Tested directly: only M. furfur, of the species tried, used PEG-35 castor oil. The rule comes from lab studies of what Malassezia yeast can feed on, and it is not a verdict on any product.

What safety reviewers say

The rating above is about pore plugging. Whether peg-40 hydrogenated castor oil is safe to use in cosmetics is a separate question. Below is the conclusion of the Cosmetic Ingredient Review (CIR), a US expert panel, and what the EU ingredient database, CosIng, lists for it. We quote CIR's conclusion as written, read on 1 November 2026.

Cosmetic Ingredient Review (US): In a 2014 review of 130 PEGylated oils, PEG-40 hydrogenated castor oil among them, the panel concluded they are “safe in the present practices of use and concentration in cosmetics when formulated to be nonirritating”. That replaced its 1997 conclusion, which had cleared PEG-40 hydrogenated castor oil for use at concentrations of up to 100%. Safety Assessment of PEGylated Oils as Used in Cosmetics, 2014 (opens in a new tab) ; 1997 report on PEG castor oils (opens in a new tab)
What it does in a product (EU CosIng): Listed as PEG-40 HYDROGENATED CASTOR OIL: surfactant (emulsifying), surfactant (cleansing). CosIng entry (opens in a new tab)
EU restrictions: None. CosIng shows no entry for it in the annexes of the EU Cosmetics Regulation.

CIR was set up in 1976 by the US cosmetics trade association, now the Personal Care Products Council, and the Council funds it. CIR states that its panel and review process are independent of the Council and the cosmetics industry. CIR's statement (opens in a new tab). The FDA does not approve cosmetic ingredients before they go on sale, except colour additives, and the companies that make and sell cosmetics are legally responsible for their safety. FDA's page (opens in a new tab).

What we make of this. CIR's conclusion does not grade pore plugging, so on its own it neither confirms nor contradicts the 2 on our list. A safety review looks at things like irritation, allergy and toxicity at the amounts products use, and the rating is only about pores, so read them side by side.

Common questions

Is PEG-40 hydrogenated castor oil comedogenic?: PEG-40 Hydrogenated Castor Oil is rated 2 on the comedogenic scale, which is the low band. We have not found a published study that grades it, so treat this number as unconfirmed.
Is PEG-40 hydrogenated castor oil non comedogenic?: Not exactly. PEG-40 Hydrogenated Castor Oil is rated 2, which is the low band rather than 0. Low and non-comedogenic are different things, and only a 0 means the second one.
What is PEG-40 hydrogenated castor oil's comedogenic rating?: 2 out of 5 on our list. It is classed as Oils. We have not found a published study that grades it, so treat this number as unconfirmed.

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.”

The rating and description above are the ones this site publishes on its A–Z list. The papers above are the ones we checked it against, and the section on who rated it says whether any of them graded this ingredient.