Ingredient review

Trideceth-15 Carboxylic Acid

INCI: TRIDECETH-15 CARBOXYLIC ACID

A gentle, non-stripping cleansing ingredient that helps remove impurities while maintaining skin comfort.

beautyskincarecleansing agent

In plain English

Trideceth-15 Carboxylic Acid is a mild cleansing agent often used in facial cleansers and makeup removers. It works by helping water mix with oil and dirt so they can be rinsed away easily. Unlike harsher soaps, it is designed to clean without leaving your skin feeling tight or dry.

Review score

Safety, usefulness, and evidence

4.0Good
4.0/ 5

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
How reviews are scored

Quick decision guide

Useful, but context matters

Trideceth-15 Carboxylic Acid 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.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging Trideceth-15 Carboxylic Acid.
  2. Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
  3. 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

low

Less likely to sting, burn, or bother most users, though sensitive skin can still react.

Clogging risk

low

Less likely to feel heavy or contribute to clogged pores for most skin types.

Evidence level

moderate

There is useful support, but formula details and claim strength still matter.

What it is

A semi-synthetic surfactant made by reacting a fatty alcohol (tridecyl alcohol) with ethylene oxide and then adding a carboxylic acid group. This structure gives it both water-loving and oil-loving properties, making it effective at lifting away sebum, makeup, and environmental debris.

How it works

In a cosmetic product, Trideceth-15 Carboxylic Acid reduces the surface tension between water and oil, allowing oily impurities to be dispersed in water and rinsed off. Its mildness comes from its large molecular structure, which is less likely to penetrate the skin barrier and cause irritation compared to smaller, harsher surfactants.

Pros

Very gentle on skin

Its large molecular structure means it cleans without penetrating deeply, reducing the risk of irritation or dryness—ideal for sensitive or compromised skin barriers.

Effective at removing oil-based impurities

It efficiently breaks down makeup, sunscreen, and excess sebum, making it a reliable choice for a second cleanse in a double-cleansing routine.

Cons and cautions

Not a deep degreaser

For very oily or acne-prone skin, this ingredient may not provide the deep cleansing feel some users prefer; a stronger surfactant might be needed for that purpose.

Semi-synthetic production

The manufacturing process involves ethoxylation, which may be a concern for consumers seeking fully natural or minimal-processing ingredients.

Best for

  • People with dry or sensitive skin looking for a gentle cleanser
  • Anyone using a double-cleansing routine who wants a mild second-step cleanser

Use caution if

  • Those who prefer exclusively natural or plant-based ingredients without any synthetic processing

Usage tips

Use in a rinse-off cleanser; avoid leaving on the skin for extended periods to prevent any potential buildup.
Pair with a gentle foaming cleanser if you need a deeper clean for oily areas like the T-zone.

Safety summary

Trideceth-15 Carboxylic Acid is considered safe for use in cosmetics at typical concentrations. It has low irritation and sensitization potential, supported by safety reviews from cosmetic ingredient panels. However, as with any ingredient, patch testing is recommended for those with known sensitivities.

Research notes

Safety assessments by the Cosmetic Ingredient Review (CIR) panel have evaluated similar ethoxylated carboxylic acids and found them safe for use in rinse-off and leave-on products. Limited specific studies on Trideceth-15 Carboxylic Acid exist, but its chemical class is well-characterized.

Common label clues

Typical concentration
Typically 1–10% in rinse-off products; lower in leave-on formulas
Regulatory status
Approved for use in cosmetics in the EU, US, and other major markets. No specific restrictions beyond general cosmetic safety requirements.
Common uses
Cleansers, Facial washes, Makeup removers, Shampoos
Environmental note
As an ethoxylated ingredient, its biodegradability can vary. Some ethoxylated surfactants may persist in the environment, though newer formulations aim to improve this profile.

Good to know

  • Trideceth-15 Carboxylic Acid is often listed near the middle of an ingredient list, indicating moderate concentration.
  • It is compatible with a wide pH range, making it versatile in formulations from acidic to neutral pH.

Common questions

What is Trideceth-15 Carboxylic Acid in beauty products?

Trideceth-15 Carboxylic Acid is a mild cleansing agent often used in facial cleansers and makeup removers. It works by helping water mix with oil and dirt so they can be rinsed away easily. Unlike harsher soaps, it is designed to clean without leaving your skin feeling tight or dry.

What does Trideceth-15 Carboxylic Acid do in a beauty product?

In a cosmetic product, Trideceth-15 Carboxylic Acid reduces the surface tension between water and oil, allowing oily impurities to be dispersed in water and rinsed off. Its mildness comes from its large molecular structure, which is less likely to penetrate the skin barrier and cause irritation compared to smaller, harsher surfactants.

Is Trideceth-15 Carboxylic Acid safe for most people?

Trideceth-15 Carboxylic Acid is considered safe for use in cosmetics at typical concentrations. It has low irritation and sensitization potential, supported by safety reviews from cosmetic ingredient panels. However, as with any ingredient, patch testing is recommended for those with known sensitivities.

Who should be careful with Trideceth-15 Carboxylic Acid?

Those who prefer exclusively natural or plant-based ingredients without any synthetic processing

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.