Ingredient review
Sodium Trideceth-4 Carboxylate
INCI: SODIUM TRIDECETH-4 CARBOXYLATE
A gentle, low-irritation surfactant that helps cleanse without stripping the skin's natural moisture barrier.
In plain English
Sodium Trideceth-4 Carboxylate is a mild cleansing ingredient that helps water mix with oil and dirt so they can be rinsed away. It's made from a fatty alcohol (tridecyl alcohol) that's been modified to be water-friendly and then turned into a salt. Because it's gentle, it's often used in products for sensitive or dry skin, and it doesn't leave skin feeling tight or dry after washing.
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
Sodium Trideceth-4 Carboxylate 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 Sodium Trideceth-4 Carboxylate.
- 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
A semi-synthetic surfactant (cleansing agent) belonging to the carboxylate family. It is produced by ethoxylating tridecyl alcohol (a fatty alcohol) and then converting it to a sodium carboxylate salt. This structure gives it both water-loving and oil-loving properties, making it effective at removing dirt, oil, and makeup.
How it works
In a cosmetic product, Sodium Trideceth-4 Carboxylate reduces the surface tension between water and oil, allowing oily impurities to be lifted from the skin and suspended in water so they can be rinsed away. Its mildness comes from its large, gentle molecular structure, which is less likely to penetrate and irritate the skin compared to harsher surfactants like sodium lauryl sulfate.
Pros
Very gentle on skin
Unlike harsher sulfates, this surfactant cleans without stripping the skin's natural oils, making it ideal for daily use on dry or sensitive skin.
Good foam and rinse feel
It produces a creamy, stable lather that rinses cleanly without leaving a residue, so skin feels refreshed but not tight.
Cons and cautions
May need co-surfactants for heavy cleansing
On its own, it may not thoroughly remove heavy makeup or waterproof sunscreen, so it's often blended with other mild cleansers.
Ethoxylation byproduct concern
As an ethoxylated ingredient, trace amounts of 1,4-dioxane can form during manufacturing. Reputable brands purify to keep levels well below safety limits.
Best for
- People with dry or sensitive skin looking for a non-stripping cleanser
- Anyone who prefers sulfate-free cleansing products
Use caution if
- Those with known allergies to ethoxylated ingredients (rare)
Usage tips
Safety summary
Sodium Trideceth-4 Carboxylate is considered safe for use in cosmetics at typical concentrations. It has low skin irritation and sensitization potential. The main safety consideration is the potential presence of 1,4-dioxane, a byproduct of ethoxylation, but reputable manufacturers purify the ingredient to meet strict safety standards. Regulatory bodies worldwide approve its use.
Research notes
Research on this specific surfactant is limited, but it belongs to a well-studied class of mild surfactants (alkyl ether carboxylates). Studies show these compounds have low irritation potential and good skin compatibility. The Cosmetic Ingredient Review (CIR) panel has reviewed similar ethoxylated surfactants and found them safe as used.
Common label clues
- Typical concentration
- 1–10% in rinse-off products; lower in leave-on formulas
- Regulatory status
- Approved for use in cosmetics globally, including by the U.S. FDA (as part of the generally recognized as safe framework) and the EU CosIng database. Manufacturers must ensure 1,4-dioxane levels are below 10 ppm (often <1 ppm).
- Common uses
- Facial cleansers, Body washes, Shampoos, Makeup removers
- Environmental note
- This surfactant is readily biodegradable and has low aquatic toxicity, making it a more environmentally friendly choice compared to some traditional surfactants.
Good to know
- Sodium Trideceth-4 Carboxylate is often found in 'sulfate-free' and 'gentle' cleansers.
- It is considered biodegradable and has a low environmental impact compared to some other surfactants.
Common questions
What is Sodium Trideceth-4 Carboxylate in beauty products?
Sodium Trideceth-4 Carboxylate is a mild cleansing ingredient that helps water mix with oil and dirt so they can be rinsed away. It's made from a fatty alcohol (tridecyl alcohol) that's been modified to be water-friendly and then turned into a salt. Because it's gentle, it's often used in products for sensitive or dry skin, and it doesn't leave skin feeling tight or dry after washing.
What does Sodium Trideceth-4 Carboxylate do in a beauty product?
In a cosmetic product, Sodium Trideceth-4 Carboxylate reduces the surface tension between water and oil, allowing oily impurities to be lifted from the skin and suspended in water so they can be rinsed away. Its mildness comes from its large, gentle molecular structure, which is less likely to penetrate and irritate the skin compared to harsher surfactants like sodium lauryl sulfate.
Is Sodium Trideceth-4 Carboxylate safe for most people?
Sodium Trideceth-4 Carboxylate is considered safe for use in cosmetics at typical concentrations. It has low skin irritation and sensitization potential. The main safety consideration is the potential presence of 1,4-dioxane, a byproduct of ethoxylation, but reputable manufacturers purify the ingredient to meet strict safety standards. Regulatory bodies worldwide approve its use.
Who should be careful with Sodium Trideceth-4 Carboxylate?
Those with known allergies to ethoxylated ingredients (rare)
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.