Found in 2,365 products in our catalogue on 30 October 2026. Hydrogenated castor oil is the hard wax made by hydrogenating castor oil. Pharmacopoeia monographs describe it as mainly the triglyceride of 12-hydroxystearic acid. It is used to structure lipsticks, balms, sticks, and deodorants, and as an emollient. SkinSenseDiary’s own safety rating is 2/10 (1 = lowest risk). It is not PEG-40 hydrogenated castor oil, and it is not liquid castor oil.
Hydrogenated castor oil (INCI: Hydrogenated Castor Oil) is the hard wax produced when castor oil is hydrogenated. Castor oil’s cosmetic INCI name is Ricinus Communis (Castor) Seed Oil. Shaw (Dermatitis, 2009) describes ricinoleic acid as the principal fatty acid of castor oil, and 12-hydroxystearic acid as the principal fatty acid of hydrogenated castor oil. Hydrogenation saturates the double bond. The two fatty acids are both 18-carbon acids with a hydroxyl group at carbon 12. They differ by that saturation. The common name is castor wax. CAS 8001-78-3 and EC 232-292-2 are the identifiers on the CosIng entry (ref. 34330), whose chemical name is “Castor oil, hydrogenated”. The European Commission says that a listing in CosIng does not mean the ingredient is approved for cosmetic use, and that CosIng does not, by itself, determine regulatory status.
The USP–NF monograph defines Hydrogenated Castor Oil as refined, bleached, hydrogenated, and deodorized castor oil, consisting mainly of not less than 70.0% of the triglyceride of hydroxystearic acid. In that monograph the fatty-acid fraction contains 78.0–91.0% 12-hydroxystearic acid, and the melting range is 85–88°C. The triglyceride assay in the same monograph sets glyceryl tri(12-hydroxystearate) at not less than 70.0%, with other glycerides allowed beside it, including di(12-hydroxystearoyl)-stearoyl-glycerol at 10.0–23.0%. European Pharmacopoeia 10.1, monograph 1497 (Castor oil, hydrogenated), describes it as the fatty oil obtained by hydrogenation of virgin castor oil, refined castor oil, or a mixture of both, consisting mainly of the triglyceride of 12-hydroxystearic acid. Those figures are acceptance criteria for material that meets the monograph. The words “hydrogenated castor oil” on a cosmetic label do not by themselves show that the lot meets USP–NF or the European Pharmacopoeia.
The 2007 CIR assessment says castor oil does not contain ricin because ricin does not partition into the oil. Hydrogenated castor oil is made from that oil, not from the pressed seed cake. That sentence is about the oil. It is not a separate ricin assay of every wax sold under this INCI name.
CosIng (ref. 34330) lists the functions as emollient, emulsifying, skin conditioning, surfactant, and viscosity controlling. Fragrance is not among them.
Search queries for “hydrogenated castor oil” often land on the PEG-40 page. These are different ingredients. PEG-40 hydrogenated castor oil is made from this wax, and then ethoxylated. Ethoxylation is what makes the PEG-40 ingredient a water-soluble solubiliser. The wax itself is not that solubiliser.
Hydrogenated Castor Oil. Hard wax at room temperature. Also called castor wax. CAS 8001-78-3.
Emollient and viscosity-controlling wax. It structures anhydrous sticks, lipsticks, balms, and deodorant sticks.
2/10 on this page (1 = lowest risk). It does not transfer to the PEG-40 ingredient.
PEG-40 Hydrogenated Castor Oil. Ethoxylated wax, about 40 ethylene oxide units on average. Used as a water-soluble solubiliser. Pharmacopoeia name: polyoxyl 40 hydrogenated castor oil.
Holds fragrance and oils in water-based products. It is not the hard structuring wax.
The PEG-40 page has its own 2/10 rating. That rating applies only to PEG-40 hydrogenated castor oil.
They are not substitutes. A formula that needs a stick to hold its shape is asking for the wax, or another structuring wax. A clear watery toner that needs to carry fragrance is asking for a solubiliser such as PEG-40 hydrogenated castor oil. Reading “castor” and “hydrogenated” in both names is not enough to tell them apart. Read the full INCI name.
Plain castor oil is also a different ingredient. Its INCI name is Ricinus Communis (Castor) Seed Oil. It is liquid at room temperature. Hydrogenated castor oil is the wax made from it.
Ricinus Communis (Castor) Seed Oil. Liquid oil. Principal fatty acid: ricinoleic acid (Shaw, 2009).
Castor oil taken by mouth is a stimulant laxative, and it has been studied for starting labour. That is ingestion of the liquid oil, not this wax on skin. Tunaru and colleagues (PNAS, 2012) traced the laxative and uterine effect of castor oil to ricinoleic acid acting on prostaglandin EP3 receptors.
Hydrogenated Castor Oil. Hard wax. Principal fatty acid: 12-hydroxystearic acid (Shaw, 2009).
Lipsticks, balms, eyebrow pencils, deodorant sticks, and other formulas that need a structuring wax and an emollient.
CosIng lists viscosity controlling. In sticks and balms the wax helps the formula hold a shape. That is a formulation job, not a treatment claim.
An emollient softens and smooths the skin. Changing the formula’s hardness, structure, or thickness is a separate function: viscosity controlling, above. The wax does not draw water the way glycerin does.
In the CIR re-review table, the 2022 lipstick range is 3.6–8%, and eyebrow pencils are 6–21%.
The same 2022 column lists non-spray underarm deodorant at 3–8.7%. FDA VCRP frequency cited by CIR was 80 underarm-deodorant uses in 2023.
The January 2025 CIR re-review summary reports how often the ingredient was registered and the concentrations in the categories above. Frequency is from FDA’s Voluntary Cosmetic Registration Program: 202 uses in 2002 and 501 uses in 2023. Concentration is from a survey the Personal Care Products Council submitted to CIR on 24 October 2022. That survey was not published as a separate journal paper. In the re-review table the 2022 column runs from 0.043% to 21%, and the 2004 column runs from 0.0003% to 39%, with other eye makeup preparations at 22–39% and lipstick at 0.5–33%. These are the values reported in the CIR re-review, not a guarantee of the percentage in a particular product. VCRP is a voluntary US register, not this site’s catalogue.
Where it shows up: anhydrous and stick formulas — lip products, eyebrow pencils, deodorant sticks — and, in our catalogue, a wide spread of other categories as well. It is there as a structuring wax and as an emollient for the skin, not as a treatment for a skin disease. People who have already reacted to castor oil, 12-hydroxystearic acid, or this wax have a reason to look for the full INCI name.
This site’s risk score is 2/10 (1 = lowest risk). The score is site-defined, and it is separate from CIR’s written conclusion below. A 2 on this page reflects an established expert safety conclusion for cosmetic use, low irritation and sensitisation in the testing that review considered, and a small number of published allergy case reports.
A small number of published case reports describe allergic contact dermatitis. Shaw (Dermatitis, 2009) described one patient who reacted to hydrogenated castor oil in an underarm deodorant and to 12-hydroxystearic acid in a lip balm. In this patient, serial dilution patch testing showed greater reactivity to the saturated hydroxylated fatty acid. Taghipour, Tatnall, and Orton (Contact Dermatitis, 2008) reported one patient reacting to the wax in a deodorant. A case report shows that a reaction can happen. It cannot estimate how common the reaction is. CIR considered the newer case reports in its 2025 re-review and still reaffirmed its conclusion.
Further reading. Taghipour, Tatnall, and Orton (Contact Dermatitis, 2008) reported one patient with axillary dermatitis from hydrogenated castor oil in a deodorant. The patch test was positive to the wax tested as is and negative to hydrogenated castor oil 30% in petrolatum. Ten controls did not develop irritant dermatitis from the wax tested as is. Shaw (Dermatitis, 2009) also recorded reactions to ricinoleic acid, castor oil, and bis-diglyceryl polyacyladipate-2, which contains 12-hydroxystearic acid. The saturation finding above comes from serial dilution tests in that one patient. Verheyden, Rombouts, Lambert, and Aerts (Cosmetics, 2017) reported two patients who reacted to castor oil tested as is and did not react to hydrogenated castor oil 30% in petrolatum. Higher concentrations of the wax were not tested in that report. Taghipour’s patient was negative at 30% in petrolatum and positive to the neat wax.
Look for Hydrogenated Castor Oil. PEG-40 Hydrogenated Castor Oil is the ethoxylated solubiliser. Ricinus Communis (Castor) Seed Oil is the liquid oil. Esters such as hydrogenated castor oil hydroxystearate are further derivatives, not this wax.
In lipsticks, balms, eyebrow pencils, and deodorant sticks it structures the stick. As an emollient, it softens and smooths the skin.
Stop that product. The published cases are a reason to name this wax, 12-hydroxystearic acid, and castor oil when a clinician plans patch tests. They are not a diagnosis, and a home test with the neat wax is not the method those reports used under controlled reading.
2022 column in the CIR re-review: lipstick 3.6–8%. Our catalogue files many lip products under Lip Care (140) rather than Lipstick (17).
2022 column in the CIR re-review: 6–21%, the highest category in that column.
2022 column in the CIR re-review: non-spray underarm deodorant 3–8.7%. Our catalogue has 88 products in the Deodorant category.
Balms often combine a hard wax with a softer occlusive. They are different materials. Petrolatum’s page covers its own refining rule.
A liquid emollient changes how stiff the stick feels. The wax is the structuring part.
Lip products sometimes list both the liquid oil and the wax. They are still two INCI names. A reaction to one does not, by itself, prove a reaction to the other. The published cases are in the safety section.
The PEG-40 ingredient is the ethoxylated solubiliser. Swapping the names will not make a watery toner into a stick, or a stick into a solubiliser.
If patch testing has already named 12-hydroxystearic acid or this wax, read the INCI list before the next stick or balm.
Laxative use and labour induction refer to liquid castor oil taken by mouth, not to this wax on skin.
Found in 2,365 products in our catalogue on 30 October 2026. This is an on-site usage statistic, not evidence of safety. Each product is counted once, under the category stored on that product. The largest categories are Moisturizer (271), Lip Care (140), Face (137), Sunscreen (129), Eyes (93), Deodorant (88), and Cleanser (88). Lip products are split across several categories. Adding Lip Care (140), Lips (83), Lip Gloss (51), Lip Balm (30), Lipstick (17), Lip Liner (9), Lip Scrub (6), and Lip Oil (4) gives 340 products. Seven of the 2,365 are filed under Non-Cosmetic. FDA VCRP’s 501 uses in 2023 are a different count, from a voluntary US register.
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