Ingredient · dataset v56
PEG-40 Hydrogenated Castor Oil and fungal acne
May trigger · Moderate evidence
Why it's a potential trigger
An ethoxylated ester of hydrogenated-castor (C18) fatty acids; Malassezia yeast's ester-cutters free the fatty half, same shape as the ruled polysorbates (polysorbate precedent, one inference step out, stated). Owner A3, approved.
Evidence strength
Moderate evidence (2/3)
Function
Fatty ester
Fatty esters: split by the yeast’s enzymes into edible fats.
Products without this ingredient
- Hada Labo Tokyo Skin Plumping Gel Cream
- Nizoral A-D Anti-Dandruff Shampoo (Ketoconazole 1%)
- AHAVA Dead Sea Water Mineral Shower Gel 6.8 oz
- SVR Sebiaclear Foaming Gel 400 ml
- FragFre Hair Styling Gel, Medium Hold, Sensitive Skin 8 fl oz
- NYX Professional Makeup Dewy Finish Long Lasting Setting Spray
Related fatty ester
- Ascorbyl Palmitate — May trigger · Moderate evidence
- Ascorbyl Tetraisopalmitate — May trigger · Moderate evidence
- Behenyl Acrylate — May trigger · Limited evidence
- Behenyl Behenate — May trigger · Limited evidence
- Bis-Octyldodecyl Dimer Dilinoleate/Propanediol Copolymer — May trigger · Moderate evidence
- Butylene Glycol Dicaprylate/Dicaprate — No known trigger
- Butyloctyl Salicylate — May trigger · Limited evidence
- C12-15 Alkyl Benzoate — May trigger · Limited evidence
Sources
EU CosIng database — search the INCI name
Last reviewed: 2026-10-13 (dataset v56).
Questions
Does PEG-40 Hydrogenated Castor Oil trigger fungal acne?
We flag it as a potential trigger (moderate evidence). That means it belongs to a class the Malassezia yeast is known to feed on — not that every product with it will cause a flare. Concentration, formulation and individual skin chemistry matter.
Does PEG-40 Hydrogenated Castor Oil feed Malassezia?
Yes: we flag PEG-40 Hydrogenated Castor Oil as a potential trigger (moderate evidence). It belongs to a class Malassezia is known to feed on — not a claim that every product with it causes a flare. Concentration, formulation and individual skin chemistry matter.
How confident is this call?
Moderate evidence: An ethoxylated ester of hydrogenated-castor (C18) fatty acids; the yeast's ester-cutters free the fatty half, same shape as the ruled polysorbates (polysorbate precedent, one inference step out, stated). Owner A3, approved.
Is this medical advice?
No. We screen ingredient lists; we never diagnose, treat, or certify products. When in doubt, ask a dermatologist.
Check a full list containing PEG-40 Hydrogenated Castor Oil →
Not medical advice: we screen ingredient lists for potential triggers — we never diagnose, treat, or certify products. Dataset v56.