Sodium lauroyl isethionate on your skin: a safety profile

What is sodium lauroyl isethionate?

The IUPAC name is sodium 2-dodecanoyloxy-ethanesulfonate.

Also known as: sodium 2-dodecanoyloxy-ethanesulfonate, SLI, sodium lauryl isethionate, DIETHYL DIMETHYLMALONATE.

IUPAC name

sodium 2-dodecanoyloxy-ethanesulfonate

CAS number

25704-94-3

Molecular formula

C14H27NaO5S

Molecular weight

330.42 g/mol

SMILES

CCCCCCCCCCCC(=O)OCCS(=O)(=O)[O-].[Na+]

PubChem CID

23668826

Regulatory consensus

1 regulatory bodyhas classified Sodium lauroyl isethionate.

Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.

Where you encounter sodium lauroyl isethionate

• soap bars
• baby shampoo
• facial cleansers
• sensitive skin products

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Sodium lauroyl isethionate:

• Decyl glucoside or other alkyl polyglucosides (APGs) — milder, plant-derived
  Trade-offs: Consumer preference for 'natural' label; many natural fragrance compounds are potent allergens (limonene, linalool, eugenol); 'natural' ≠ 'safe'; often more expensive than synthetic equivalents.
  Relative cost: 2-5× conventional
• Sodium cocoyl isethionate (SCI) — low irritation potential
  Trade-offs: Alternative surfactant; performance characteristics (foaming, emulsification, wetting) vary; biodegradability and aquatic toxicity should be assessed; formulation adjustment may be needed.
  Relative cost: 1.2-2×
• Sodium lauroyl glutamate — amino acid-based, very mild
  Trade-offs: Extremely mild (pH 5.5-6.5); biodegradable; derived from amino acids and fatty acids; premium ingredient cost; excellent consumer perception; lower foam volume than sulfate surfactants.
  Relative cost: 1.2-2×
• Cocamidopropyl betaine (amphoteric) — gentler than anionic surfactants
  Trade-offs: Removes 95-99% of dissolved contaminants including metals, PFAS, nitrates; wastes 2-4 gallons per gallon produced (improving with newer systems); removes beneficial minerals; $0.05-0.25/gallon; requires pre-treatment for longevity.
  Relative cost: 1.2-2×

Frequently asked questions