Sodium Isethionate

What is Sodium Isethionate?

Sodium Isethionate is the sodium salt of isethionic acid, a compound featuring a hydroxy group and sulfonic acid functionality, often produced from coconut-derived fatty acids or through synthetic processes. In cosmetics, it acts as a key anionic surfactant mainly in rinse-off formulations such as shampoos, body washes, facial cleansers, and soap bars. It works by decreasing water's surface tension, which enables effective emulsification of oils and soils into micelles that rinse away cleanly. This mechanism supports thorough yet non-disruptive cleansing. Additionally, its structure allows for humectant-like properties and emolliency, contributing to a smooth after-feel on skin and hair surfaces. Formulators value its high foam quality, stability across pH ranges, and compatibility with other surfactants in mild, sulfate-free systems designed for daily use.

Comedogenic Rating 0/5 Low risk of clogging pores

EWG Safety Rating 1 View on EWG →

PubChem View on PubChem →

Roles in Formulation

This ingredient serves the following purposes in cosmetic formulations:

Antistatic agent

Reduces static electricity and flyaways by improving surface conductivity, enhancing hair manageability and smoothness in conditioners and styling products.

Cleansing agent

Removes dirt, oil, and impurities by lowering surface tension and forming micelles, enabling soils to be lifted and rinsed away from skin, hair, or teeth.

Hair conditioning

Improves softness, shine, and manageability by reducing friction and static; commonly achieved with cationic agents, silicones, oils, or conditioning polymers.

Skin conditioning agent

Maintains skin softness, smoothness, and flexibility.

Benefits

Provides gentle cleansing by effectively removing dirt and oils without harshness.

Enhances skin and hair smoothness through conditioning effects.

Minimizes static electricity for better manageability in hair products.

Who It's For

A quick guide for who this ingredient may suit (and who should be cautious).

Who May Benefit	Who Should Avoid
Individuals with sensitive skin seeking mild cleansers.	Those with rare allergies to sulfonic acid salts.
People with dry or frizzy hair needing conditioning surfactants.	People experiencing irritation from acyl isethionates.
Users preferring sulfate-free personal care products.	Individuals with compromised skin barriers during acute flares.

Safety Notes

Rated low hazard by EWG with scores of 1 across assessments.
Deemed safe for cosmetic use by Cosmetic Ingredient Review.

Frequently Asked Questions about Sodium Isethionate

What is Sodium Isethionate?

A mild anionic surfactant derived from isethionic acid, used in cleansers for gentle dirt removal and conditioning.

Is it safe for sensitive skin?

Yes, it carries a low hazard rating and is suitable for mild formulations per safety reviews.

Does it cause breakouts?

It has a comedogenic rating of 0, indicating low likelihood of pore clogging.