Ingredient review
PEG-29 Castor Oil
INCI: PEG-29 Castor Oil
PEG-29 Castor Oil is a gentle cleansing and emulsifying ingredient, but its PEG component raises mild concerns about potential impurities.
In plain English
PEG-29 Castor Oil is a lab-made ingredient that combines castor oil with a chain of ethylene oxide molecules (the 'PEG' part). This makes the oil water-soluble, so it can help mix oil and water in products like cleansers and shampoos. It also helps remove dirt and makeup without stripping the skin too harshly. However, the manufacturing process can sometimes leave behind trace impurities like 1,4-dioxane, which is why some people prefer to avoid PEG ingredients.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Main practical flags: irritation is moderate; clogging risk is low.
- Source
- semi synthetic
- Evidence
- moderate
- Irritation
- moderate
- Clogging risk
- low
Quick decision guide
Useful, but context matters
PEG-29 Castor Oil can be useful, but watch for some irritation potential.
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-29 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
moderateCan bother some users, especially with frequent use, damaged skin, or strong companion ingredients.
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-29 Castor Oil is a semi-synthetic compound created by reacting castor oil with 29 units of ethylene oxide. It belongs to the PEG (polyethylene glycol) family of emulsifiers and surfactants.
How it works
In a cosmetic product, PEG-29 Castor Oil acts as a surfactant, reducing the surface tension between oil and water so they can blend. This helps the product spread easily, lift away dirt and oil from the skin or hair, and rinse off cleanly. It also stabilizes emulsions, preventing the oil and water phases from separating.
Pros
Gentle cleansing
PEG-29 Castor Oil removes dirt and makeup effectively without the harshness of traditional sulfates, making it suitable for daily use on normal skin.
Good emulsifier
It helps blend oil and water in formulas, creating stable, creamy textures that feel pleasant on the skin and rinse off easily.
Cons and cautions
Potential impurities
The PEG manufacturing process can leave trace amounts of 1,4-dioxane, a possible carcinogen, though reputable brands purify their ingredients to minimize this risk.
May be drying over time
Frequent use in high concentrations can strip natural oils from the skin, especially for those with dry or sensitive skin types.
Best for
- People with normal to oily skin looking for a gentle cleanser
- Those who use makeup and want an effective but mild makeup remover
Use caution if
- Individuals with very dry or compromised skin who prefer sulfate-free, non-PEG cleansers
Usage tips
Safety summary
PEG-29 Castor Oil is considered safe in rinse-off products at typical concentrations. The main concern is the potential for 1,4-dioxane contamination, which is regulated and minimized by quality manufacturers. It has low comedogenic risk and moderate irritation potential for sensitive skin.
Research notes
Studies on PEG derivatives indicate low acute toxicity and skin irritation at low concentrations. The Cosmetic Ingredient Review (CIR) panel has reviewed PEG compounds and found them safe as used, with the caveat that manufacturers should ensure low 1,4-dioxane levels.
Common label clues
- Typical concentration
- 1% to 10% depending on product type
- Regulatory status
- Approved for use in cosmetics in the US, EU, and many other regions, with concentration limits for leave-on products in some countries.
- Common uses
- Cleansers, Shampoos, Conditioners, Bath products, Makeup removers
- Environmental note
- PEG compounds are generally biodegradable, but the manufacturing process has an environmental footprint due to the use of ethylene oxide.
Good to know
- PEG-29 Castor Oil is often listed as a 'PEG' ingredient; if you prefer to avoid PEGs entirely, look for alternatives like glucosides.
- The number '29' refers to the average number of ethylene oxide units, which affects its water solubility and mildness.
Common questions
What is PEG-29 Castor Oil in beauty products?
PEG-29 Castor Oil is a lab-made ingredient that combines castor oil with a chain of ethylene oxide molecules (the 'PEG' part). This makes the oil water-soluble, so it can help mix oil and water in products like cleansers and shampoos. It also helps remove dirt and makeup without stripping the skin too harshly. However, the manufacturing process can sometimes leave behind trace impurities like 1,4-dioxane, which is why some people prefer to avoid PEG ingredients.
What does PEG-29 Castor Oil do in a beauty product?
In a cosmetic product, PEG-29 Castor Oil acts as a surfactant, reducing the surface tension between oil and water so they can blend. This helps the product spread easily, lift away dirt and oil from the skin or hair, and rinse off cleanly. It also stabilizes emulsions, preventing the oil and water phases from separating.
Is PEG-29 Castor Oil safe for most people?
PEG-29 Castor Oil is considered safe in rinse-off products at typical concentrations. The main concern is the potential for 1,4-dioxane contamination, which is regulated and minimized by quality manufacturers. It has low comedogenic risk and moderate irritation potential for sensitive skin.
Who should be careful with PEG-29 Castor Oil?
Individuals with very dry or compromised skin who prefer sulfate-free, non-PEG cleansers
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.