Sodium Cocoyl Isethionate

Also known as: SCI, Sodium coconut isethionate, Baby-foam surfactant

A coconut-fatty-acid-derived anionic surfactant valued for dense foam and generally milder cleansing than soap.

Editorial review by the IngredientWiki Editorial Team
Updated 2026-09-28
4 sources
1 min read
Report an error

White surfactant noodles, coconut shell, and soft cleanser foam — Editorial illustration

Sodium cocoyl isethionate (SCI) is an anionic surfactant made from coconut-derived fatty acids and isethionate. It creates creamy foam and is widely used in syndet bars and solid cleansers. 'Sulfate-free' describes its chemistry, not a guarantee that every SCI formula is non-irritating.^{1, 2, 3}

A surfactant, not a sulfate detergent^{1, 3}
Common in syndet bars and solid shampoo^{1, 3}
Often milder than alkaline soap^{1, 3}
Irritation depends on the full surfactant blend and pH^{1, 3}

What is Sodium Cocoyl Isethionate?

SCI is a family material because the cocoyl portion contains several coconut fatty-acid chains. Its solid form and foam profile make it especially useful in low-water cleansing bars.^{1, 3}

Where it comes from

Natural sources

Fatty acids originally derived from coconut or similar vegetable oils

How it's made

Fatty acids are reacted with isethionate and converted to the sodium salt; the final surfactant is manufactured rather than simply pressed coconut oil.

What it does in products

Benefits

Creamy cleansing foam

moderate evidence

SCI creates fine, dense foam and removes oily soil by forming micelles in water.^{1, 2}

Its technical surfactant function is established; user experience still depends on the blend and use level.

Milder syndet-bar option

moderate evidence

Comparative work supports lower barrier disruption for well-formulated syndet systems than for harsher detergents or high-pH soap.^{2, 3}

The evidence is formulation-level and cannot rank raw surfactants in isolation for every user.

Automatically non-irritating

insufficient evidence

SCI can still sting eyes or irritate skin at unsuitable concentration, pH, or contact time.^{1, 3}

A sulfate-free label is not an irritation study.

Evidence scope and limitations

SCI in rinse-off syndet formulations is covered; raw-material exposure and occupational inhalation are separate scenarios.

Most tolerability evidence tests complete bars rather than isolated SCI.
Surfactant mildness changes with pH, blend, dose, and washing behavior.

Evidence last checked: 2026-09-28

Side effects & safety

Dryness or tightness (varies)More likely with frequent washing or an aggressive blend.

Eye irritation (uncommon)Rinse thoroughly if product enters the eyes.

Safety considerations

No pharmacologic interactions expected
Not for: Known reaction to the finished cleanser
Not for: Use of raw surfactant powder directly on skin

^{1, 3}

Amounts studied & product use

These figures describe research or common product use, not a personal dose or treatment recommendation.

In skincare studies and products

SCI is used as part of a formulated surfactant system, especially in bars and powdered cleansers. Percentage, pH, co-surfactants, and rinse time determine performance; raw SCI is not a ready-to-use cleanser.

^{1, 2}

Regulatory status

Used as a cosmetic cleansing ingredient in the United States; finished cosmetic safety is the manufacturer's responsibility.
INCI name on cosmetic labels: Sodium Cocoyl Isethionate.
CIR safety materials address isethionate surfactants under cosmetic conditions of use.

^{4, 1}

Syndet bar is not the same as soap

Soap is an alkaline fatty-acid salt. A syndet bar is structured from synthetic detergents and can be formulated closer to skin's natural pH. The solid shape does not tell you which chemistry is inside.

^{2, 3}

Frequently asked questions

Is SCI a sulfate?

No. It is an isethionate surfactant and has different chemical structure from SLS or SLES.^{1, 2, 3}

Is it natural?

Its fatty acids may begin with coconut oil, but SCI is a manufactured surfactant.^{1, 2, 3}

Can SCI irritate sensitive skin?

Yes. It is often used in milder systems, but the complete cleanser and washing pattern matter.^{1, 2, 3}

The bottom line

SCI is a useful mild-syndet building block, not a universal sensitive-skin guarantee.

References

Sodium cocoyl isethionate ingredient record and safety documents. Cosmetic Ingredient Review (2026) · safety assessment
In-use tolerability of two new syndet bars with sodium cocoyl isethionate, disodium lauryl sulfosuccinate and wheat starch as major ingredients in differing relations: results of a cross-over trial. International Journal of Cosmetic Science (1992) · randomized trial · PMID 19272112
Biophysical characterization of skin damage and recovery after exposure to different surfactants. Contact Dermatitis (1999) · primary study · PMID 10048655
FDA Authority Over Cosmetics: How Cosmetics Are Not FDA-Approved, but Are FDA-Regulated. U.S. Food and Drug Administration (2013) · government guidance

Revision history

2026-09-28Initial publication with claim-level citations, formulation limits, safety context, and editorial evidence review.