Ingredient review
Ceteareth-18
INCI: Ceteareth-18
Ceteareth-18 is a reliable emulsifier that helps keep your creams and lotions smooth and stable, but it may be contaminated with 1,4-dioxane during manufacturing.
In plain English
Ceteareth-18 is a synthetic ingredient that helps oil and water mix together in products like moisturizers and cleansers. Without it, many creams would separate into watery and oily layers. It is part of a family of ingredients called ethoxylated alcohols, which are made by reacting fatty alcohols with ethylene oxide. While it is generally safe and widely used, the manufacturing process can produce a trace impurity called 1,4-dioxane, which is a potential concern for some people.
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
- synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Ceteareth-18 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 Ceteareth-18.
- 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
Ceteareth-18 is a synthetic emulsifier derived from cetearyl alcohol (a blend of cetyl and stearyl alcohols) that has been reacted with 18 units of ethylene oxide. It belongs to the ceteareth family of ingredients, which are commonly used in cosmetics to stabilize oil-in-water emulsions.
How it works
Ceteareth-18 works by reducing the surface tension between oil and water molecules, allowing them to blend into a stable, uniform cream or lotion. Its long ethylene oxide chain (18 units) makes it water-soluble, so it helps disperse tiny oil droplets throughout the water phase, preventing separation over time.
Pros
Effective emulsifier
Ceteareth-18 reliably blends oil and water, giving your creams and lotions a smooth, uniform texture that stays stable on the shelf.
Low irritation risk
At typical concentrations, it is unlikely to cause stinging or redness, making it suitable for most skin types.
Cons and cautions
Potential 1,4-dioxane contamination
As an ethoxylated ingredient, Ceteareth-18 can contain trace amounts of 1,4-dioxane, a byproduct that some consumers prefer to avoid.
May be drying for sensitive skin
In high concentrations, ethoxylated emulsifiers can strip natural oils, potentially leading to dryness or irritation for very sensitive skin.
Best for
- People who use creams and lotions and want a stable, non-separating texture
- Those with normal to combination skin looking for a reliable emulsifier in their products
Use caution if
- Individuals with very sensitive or reactive skin who prefer to avoid ethoxylated ingredients due to potential 1,4-dioxane concerns
Usage tips
Safety summary
Ceteareth-18 is considered safe for use in cosmetics at typical concentrations. The main safety concern is potential contamination with 1,4-dioxane, a byproduct of ethoxylation. Reputable manufacturers use purification steps to minimize this impurity. Regulatory bodies like the Cosmetic Ingredient Review (CIR) have deemed it safe as used.
Research notes
Research on Ceteareth-18 specifically is limited, but the broader ceteareth family has been reviewed by the Cosmetic Ingredient Review (CIR) panel, which found them safe in cosmetic formulations. Studies focus on irritation potential and impurity profiles rather than direct skin benefits.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics by the FDA and the European Commission, with no concentration restrictions. However, 1,4-dioxane is regulated as a contaminant in some regions.
- Common uses
- Moisturizers, Cleansers, Lotions, Creams
- Environmental note
- Ceteareth-18 is synthetic and not readily biodegradable. Its production involves ethylene oxide, which is derived from fossil fuels.
Good to know
- Ceteareth-18 is often used alongside other ceteareth numbers (like Ceteareth-20) to fine-tune emulsion texture.
- The number '18' refers to the length of the polyethylene glycol chain, which affects water solubility.
- Many brands now voluntarily purify their ethoxylated ingredients to reduce 1,4-dioxane levels.
Common questions
What is Ceteareth-18 in beauty products?
Ceteareth-18 is a synthetic ingredient that helps oil and water mix together in products like moisturizers and cleansers. Without it, many creams would separate into watery and oily layers. It is part of a family of ingredients called ethoxylated alcohols, which are made by reacting fatty alcohols with ethylene oxide. While it is generally safe and widely used, the manufacturing process can produce a trace impurity called 1,4-dioxane, which is a potential concern for some people.
What does Ceteareth-18 do in a beauty product?
Ceteareth-18 works by reducing the surface tension between oil and water molecules, allowing them to blend into a stable, uniform cream or lotion. Its long ethylene oxide chain (18 units) makes it water-soluble, so it helps disperse tiny oil droplets throughout the water phase, preventing separation over time.
Is Ceteareth-18 safe for most people?
Ceteareth-18 is considered safe for use in cosmetics at typical concentrations. The main safety concern is potential contamination with 1,4-dioxane, a byproduct of ethoxylation. Reputable manufacturers use purification steps to minimize this impurity. Regulatory bodies like the Cosmetic Ingredient Review (CIR) have deemed it safe as used.
Who should be careful with Ceteareth-18?
Individuals with very sensitive or reactive skin who prefer to avoid ethoxylated ingredients due to potential 1,4-dioxane concerns
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.