Ingredient review

Sodium Trideceth-8 Carboxylate

INCI: SODIUM TRIDECETH-8 CARBOXYLATE

A gentle, semi-synthetic surfactant that cleanses effectively while being less likely to irritate or dry out the skin compared to harsher detergents.

beautyskincarecleanser

In plain English

Sodium Trideceth-8 Carboxylate is a mild cleansing ingredient often used in soaps and shampoos. It helps lift dirt, oil, and makeup from the skin and hair so they can be rinsed away with water. Because it's less harsh than some other cleansers, it's a good choice for people with sensitive or dry skin.

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

Sodium Trideceth-8 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.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging Sodium Trideceth-8 Carboxylate.
  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 converting it into a carboxylate salt. It belongs to a class of mild cleansers known as alkyl ether carboxylates.

How it works

It works by reducing the surface tension between water and oil, allowing water to mix with and wash away oily impurities. Its molecular structure has a water-loving head and an oil-loving tail, which surrounds and lifts dirt and sebum from the skin so they can be rinsed off.

Pros

Very gentle on skin

Unlike harsher sulfates, this surfactant cleanses without stripping the skin's moisture barrier, making it suitable for daily use and sensitive skin.

Good foam and rinseability

It produces a stable, creamy lather that rinses cleanly, leaving skin feeling soft rather than tight or dry.

Cons and cautions

Semi-synthetic production

It is made through chemical processing (ethoxylation), which may be a concern for consumers who prefer entirely natural or minimally processed ingredients.

Potential for mild irritation at high levels

While generally mild, very high concentrations (above 10%) can still cause slight dryness or irritation, especially on compromised skin.

Best for

  • People with normal to dry skin looking for a gentle cleanser
  • Those with sensitive skin who react to stronger detergents like sodium lauryl sulfate

Use caution if

  • Individuals with known allergies to ethoxylated ingredients (rare)
  • Those seeking a completely natural, plant-only ingredient list

Usage tips

Look for it in sulfate-free cleansers for a gentler wash experience.
Pair with moisturizing ingredients like glycerin or ceramides in your routine if you have very dry skin.
Use lukewarm water when cleansing to avoid over-drying, even with mild surfactants.

Safety summary

Sodium Trideceth-8 Carboxylate is considered safe for use in cosmetics at typical concentrations. It has low irritation and sensitization potential, making it a preferred choice for sensitive-skin formulations. As with any ingredient, patch testing is recommended for those with known sensitivities.

Research notes

Alkyl ether carboxylates like Sodium Trideceth-8 Carboxylate have been studied for their mildness and are widely used in dermatologist-recommended cleansers. They are less damaging to the skin barrier than traditional sulfates, though individual studies on this specific variant are limited.

Common label clues

Typical concentration
1–10% in rinse-off products; lower in leave-on products
Regulatory status
Approved for use in cosmetics in the EU, US, and other major markets. No known restrictions at typical use levels.
Common uses
Facial cleansers, Body washes, Shampoos, Makeup removers
Environmental note
This ingredient is generally considered biodegradable, but its ethoxylate chain means it is not fully natural. Some environmental groups prefer plant-based, non-ethoxylated alternatives.

Good to know

  • Sodium Trideceth-8 Carboxylate is often used alongside other mild surfactants to create a balanced cleansing formula.
  • It is considered biodegradable and is commonly found in eco-friendly product lines.

Common questions

What is Sodium Trideceth-8 Carboxylate in beauty products?

Sodium Trideceth-8 Carboxylate is a mild cleansing ingredient often used in soaps and shampoos. It helps lift dirt, oil, and makeup from the skin and hair so they can be rinsed away with water. Because it's less harsh than some other cleansers, it's a good choice for people with sensitive or dry skin.

What does Sodium Trideceth-8 Carboxylate do in a beauty product?

It works by reducing the surface tension between water and oil, allowing water to mix with and wash away oily impurities. Its molecular structure has a water-loving head and an oil-loving tail, which surrounds and lifts dirt and sebum from the skin so they can be rinsed off.

Is Sodium Trideceth-8 Carboxylate safe for most people?

Sodium Trideceth-8 Carboxylate is considered safe for use in cosmetics at typical concentrations. It has low irritation and sensitization potential, making it a preferred choice for sensitive-skin formulations. As with any ingredient, patch testing is recommended for those with known sensitivities.

Who should be careful with Sodium Trideceth-8 Carboxylate?

Individuals with known allergies to ethoxylated ingredients (rare) Those seeking a completely natural, plant-only ingredient list

Research sources

Cosmetic Ingredient Review (CIR) – Safety Assessment of Alkyl Ether CarboxylatesOpenPubChem – Sodium Trideceth-8 CarboxylateOpenEWG Skin Deep – Sodium Trideceth-8 CarboxylateOpen

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.