Ingredient review
Trideceth-5
INCI: TRIDECETH-5
A mild synthetic emulsifier that helps mix oil and water in cleansers and lotions, generally safe but may be drying for very sensitive skin.
In plain English
Trideceth-5 is a man-made ingredient that helps oil and water stay mixed together in products like face washes and lotions. It's a type of surfactant, which means it can also help lift dirt and oil from your skin so they rinse away with water. Think of it as a gentle helper that keeps your product smooth and effective without being harsh.
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
Trideceth-5 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 Trideceth-5.
- 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
Trideceth-5 is a synthetic ethoxylated alcohol, specifically a polyethylene glycol (PEG) derivative of tridecyl alcohol. It belongs to the 'eth' family of surfactants and is produced through a chemical process that makes it water-soluble and able to stabilize mixtures of oil and water.
How it works
In a cosmetic product, Trideceth-5 sits at the boundary between oil and water droplets, reducing surface tension so they don't separate. This creates a stable, uniform lotion or cleanser. When used in cleansers, it also helps break down sebum and makeup, allowing them to be rinsed off easily.
Pros
Effective emulsifier
Trideceth-5 reliably keeps oil and water blended, so your lotion or cleanser stays smooth and doesn't separate on the shelf.
Mild on skin
Compared to stronger surfactants like sodium lauryl sulfate, Trideceth-5 is considered gentle and less likely to cause irritation or redness.
Cons and cautions
Potential for dryness
In high concentrations or for very dry skin, it can still remove too much natural oil, leading to tightness or flakiness.
Ethoxylation concerns
As a PEG compound, it may contain trace amounts of 1,4-dioxane (a potential carcinogen) if not thoroughly purified, though reputable brands ensure low levels.
Best for
- People with normal to combination skin looking for a gentle cleanser
- Anyone using lotions or creams that need a stable texture
Use caution if
- Those with extremely dry or compromised skin barriers who may find it slightly drying
Usage tips
Safety summary
Trideceth-5 is considered safe for use in cosmetics at typical concentrations. The main safety concern is the potential presence of 1,4-dioxane, but reputable manufacturers purify their ingredients to meet safety standards. It is generally non-irritating and non-comedogenic.
Research notes
Studies on ethoxylated alcohols like Trideceth-5 indicate low acute toxicity and skin irritation potential. The Cosmetic Ingredient Review (CIR) panel has reviewed similar PEG alkyl ethers and found them safe when formulated to minimize impurities.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics in the US (FDA) and EU (CosIng) at concentrations up to 5% in rinse-off products and lower in leave-on products.
- Common uses
- Cleansers, Shampoos, Body washes, Lotions
- Environmental note
- As a synthetic PEG compound, it is not readily biodegradable and may persist in water systems, though it is used in low concentrations.
Good to know
- Trideceth-5 is often used alongside other emulsifiers to create a more balanced formula.
- It is not a foaming agent, so products with it may have a low-lather texture.
Common questions
What is Trideceth-5 in beauty products?
Trideceth-5 is a man-made ingredient that helps oil and water stay mixed together in products like face washes and lotions. It's a type of surfactant, which means it can also help lift dirt and oil from your skin so they rinse away with water. Think of it as a gentle helper that keeps your product smooth and effective without being harsh.
What does Trideceth-5 do in a beauty product?
In a cosmetic product, Trideceth-5 sits at the boundary between oil and water droplets, reducing surface tension so they don't separate. This creates a stable, uniform lotion or cleanser. When used in cleansers, it also helps break down sebum and makeup, allowing them to be rinsed off easily.
Is Trideceth-5 safe for most people?
Trideceth-5 is considered safe for use in cosmetics at typical concentrations. The main safety concern is the potential presence of 1,4-dioxane, but reputable manufacturers purify their ingredients to meet safety standards. It is generally non-irritating and non-comedogenic.
Who should be careful with Trideceth-5?
Those with extremely dry or compromised skin barriers who may find it slightly drying
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.