Ingredient review
PEG-35 Castor Oil
INCI: PEG-35 Castor Oil
PEG-35 Castor Oil is a reliable emulsifier that helps mix oil and water, making it a staple in many cleansers and creams without causing irritation.
In plain English
PEG-35 Castor Oil is a modified version of castor oil that has been treated with polyethylene glycol (PEG) to make it water-friendly. In simple terms, it acts like a bridge between oil and water, allowing them to blend smoothly. This is why you'll find it in products like makeup removers and lotions, where it helps create a stable, creamy texture. It's generally very gentle on the skin and unlikely to clog pores.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- semi synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
PEG-35 Castor Oil is generally a lower-concern ingredient when the full formula suits your skin.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging PEG-35 Castor Oil.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.
Score terms in plain English
Irritation risk
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
PEG-35 Castor Oil is a semi-synthetic ingredient created by reacting castor oil with ethylene oxide (PEG). The '35' refers to the average number of ethylene oxide units, which determines its water solubility and mildness. It is a clear to slightly yellow liquid that functions primarily as an emulsifier and surfactant.
How it works
In a cosmetic product, PEG-35 Castor Oil reduces the surface tension between oil and water, allowing them to mix into a stable emulsion. This prevents the product from separating into layers. As a surfactant, it also helps lift dirt, oil, and makeup from the skin so they can be rinsed away with water.
Pros
Gentle on skin
PEG-35 Castor Oil is well-tolerated by most skin types, including sensitive skin, and rarely causes irritation or breakouts.
Versatile emulsifier
It helps create smooth, stable formulas in a wide range of products, from lightweight lotions to rich cleansing balms.
Cons and cautions
Potential contaminant concern
The ethoxylation process can leave trace amounts of 1,4-dioxane, a possible carcinogen, though reputable manufacturers purify it to safe levels.
Not for PEG-free routines
If you prefer to avoid PEG compounds for personal or environmental reasons, this ingredient won't fit your criteria.
Best for
- Anyone looking for a gentle, non-irritating makeup remover or cleanser
- People with oily or combination skin who need effective but mild cleansing
Use caution if
- Individuals with known sensitivities to PEG compounds or ethoxylated ingredients
Usage tips
Safety summary
PEG-35 Castor Oil is considered safe for cosmetic use at typical concentrations. The main safety consideration is the potential for trace 1,4-dioxane contamination, which is regulated and minimized by responsible manufacturers. Overall, it poses a low risk of irritation or comedogenicity.
Research notes
Research on PEG-35 Castor Oil focuses on its function as an emulsifier and surfactant. Studies confirm its low irritation potential and effectiveness in stabilizing emulsions. The safety of PEG compounds has been reviewed by the Cosmetic Ingredient Review (CIR) panel, which found them safe as used in cosmetics.
Common label clues
- Typical concentration
- 1% to 5%
- Regulatory status
- Approved for use in cosmetics by the FDA and the European Commission, with no concentration restrictions. Manufacturers are expected to keep 1,4-dioxane levels below 10 ppm.
- Common uses
- Cleansers, Makeup removers, Lotions, Creams
- Environmental note
- Castor oil is a renewable plant resource, but the ethoxylation process involves synthetic chemistry and may have a moderate environmental footprint depending on manufacturing practices.
Good to know
- PEG-35 Castor Oil is often used in 'oil cleansers' that turn milky when mixed with water, making rinsing easy.
- The number '35' indicates the degree of ethoxylation, which affects how water-soluble the ingredient is.
Common questions
What is PEG-35 Castor Oil in beauty products?
PEG-35 Castor Oil is a modified version of castor oil that has been treated with polyethylene glycol (PEG) to make it water-friendly. In simple terms, it acts like a bridge between oil and water, allowing them to blend smoothly. This is why you'll find it in products like makeup removers and lotions, where it helps create a stable, creamy texture. It's generally very gentle on the skin and unlikely to clog pores.
What does PEG-35 Castor Oil do in a beauty product?
In a cosmetic product, PEG-35 Castor Oil reduces the surface tension between oil and water, allowing them to mix into a stable emulsion. This prevents the product from separating into layers. As a surfactant, it also helps lift dirt, oil, and makeup from the skin so they can be rinsed away with water.
Is PEG-35 Castor Oil safe for most people?
PEG-35 Castor Oil is considered safe for cosmetic use at typical concentrations. The main safety consideration is the potential for trace 1,4-dioxane contamination, which is regulated and minimized by responsible manufacturers. Overall, it poses a low risk of irritation or comedogenicity.
Who should be careful with PEG-35 Castor Oil?
Individuals with known sensitivities to PEG compounds or ethoxylated ingredients
Research sources
Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.