Ingredient review
Potassium Trideceth-4 Carboxylate
INCI: POTASSIUM TRIDECETH-4 CARBOXYLATE
A gentle, low-irritation surfactant that cleanses effectively while being kind to sensitive skin.
In plain English
This ingredient is a mild soap-like molecule that helps water mix with oil and dirt so they can be rinsed away. It's made from fatty acids (similar to those in coconut oil) and a small amount of processed ethylene oxide, which makes it less harsh than traditional soaps. Because it's gentle, it's often used in products for sensitive or dry skin.
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
Potassium 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 Potassium 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) created by reacting a fatty alcohol (tridecyl alcohol) with ethylene oxide and then adding a carboxylate group to make it water-soluble and mild.
How it works
It reduces the surface tension between water and oil, allowing oils and dirt on the skin to be lifted away and rinsed off. Its large molecular structure makes it less penetrating and less irritating than smaller surfactants.
Pros
Very gentle on skin
Its large molecular structure means it doesn't penetrate deeply, reducing the risk of irritation and making it ideal for sensitive skin types.
Effective cleanser without sulfates
It removes oil and makeup effectively without the harshness of sodium lauryl sulfate, so your skin feels clean but not stripped.
Cons and cautions
Potential for trace impurities
As an ethoxylated ingredient, it may contain trace amounts of 1,4-dioxane, a byproduct that is regulated to safe levels in cosmetics.
Can be slightly drying with overuse
While mild, using a cleanser with this ingredient more than twice a day may still lead to some dryness, especially for very dry skin.
Best for
- People with sensitive or easily irritated skin
- Those looking for a sulfate-free cleanser
Use caution if
- Individuals with known allergies to ethoxylated ingredients (rare)
Usage tips
Safety summary
Considered safe for use in cosmetics at typical concentrations. The main concern is trace 1,4-dioxane, which is tightly regulated. For most people, it poses very low risk of irritation or allergy.
Research notes
Studies show that ethoxylated carboxylates like this one have low skin irritation potential compared to traditional anionic surfactants. Regulatory bodies (e.g., CIR, SCCS) have reviewed similar ingredients and found them safe within recommended limits.
Common label clues
- Typical concentration
- 1–10% in rinse-off products; lower in leave-on formulations
- Regulatory status
- Approved for use in cosmetics in the EU, US, and other major markets. Trace 1,4-dioxane is regulated to ≤10 ppm in the EU and ≤50 ppm in the US.
- Common uses
- Facial cleansers, Body washes, Makeup removers, Shampoos
- Environmental note
- Biodegradable under aerobic conditions, but ethoxylation process has some environmental footprint. Generally considered safer for aquatic life than non-biodegradable surfactants.
Good to know
- Often found in 'sulfate-free' and 'gentle' cleansers
- Biodegradable, making it a more environmentally friendly choice compared to some traditional surfactants
Common questions
What is Potassium Trideceth-4 Carboxylate in beauty products?
This ingredient is a mild soap-like molecule that helps water mix with oil and dirt so they can be rinsed away. It's made from fatty acids (similar to those in coconut oil) and a small amount of processed ethylene oxide, which makes it less harsh than traditional soaps. Because it's gentle, it's often used in products for sensitive or dry skin.
What does Potassium Trideceth-4 Carboxylate do in a beauty product?
It reduces the surface tension between water and oil, allowing oils and dirt on the skin to be lifted away and rinsed off. Its large molecular structure makes it less penetrating and less irritating than smaller surfactants.
Is Potassium Trideceth-4 Carboxylate safe for most people?
Considered safe for use in cosmetics at typical concentrations. The main concern is trace 1,4-dioxane, which is tightly regulated. For most people, it poses very low risk of irritation or allergy.
Who should be careful with Potassium Trideceth-4 Carboxylate?
Individuals 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.