Common Name(s): Isobutyl stearate,isobutanol (branched c4) stearic acid (c18) ester
DESCRIPTION
What It Does: Softens and conditions skin with a light, non-greasy feel.
Why It's Used: Used for its medium-light branched ester; liquid due to branching; non-greasy; good spreading emollient properties; suitable for lightweight skin care where non-greasy texture is key.
How It Works: Ester of isobutanol (branched c4) (branched or specialty alcohol) with stearic acid (c18); branching reduces crystallinity and greasiness; provides smooth, dry-oil skin feel.
Typically Found In: Lightweight moisturizers,sunscreens,skin serums,body lotions
TECHNICAL DETAILS
Primary Category: Functional ingredient – emollient
Secondary Functions: Skin conditioning,texture modification,spreading agent
Application Areas:
Facial Skincare
Body Care
Hair Care
Beard Care
Color Cosmetics (Makeup)
Dietary/Oral Supplements
Typical Concentration Range: 0.5%–10%
SOURCING & ETHICS
Vegan Status: Conditional - feedstock declaration required
Halal Status: Unverified - feedstock declaration required (plant, animal and petrochemical routes all exist)
Source Notes: Isobutanol (branched c4) and stearic acid (c18); plant or synthetic origin. [audit 2026-07-29 rev2: origin-dependent: the same inci exists in plant, animal and petrochemical versions and the name does not discriminate. determination requires shariah-panel sign-off.]
SKIN COMPATIBILITY
Irritancy Rating: 1/5 – very low
Comedogenicity Rating: 1/5 – low
Sensitivity Concerns: Generally well tolerated.
Safe for Sensitive Skin: Yes
SAFETY & COMPATIBILITY
Safety Profile: Good safety profile. ewg score: 1.
Works Well With: Other emollients,silicones,natural oils,humectants
Avoid Combining With: No significant incompatibilities
SCIENTIFIC NOTE
Isobutyl stearate: branched c4 isobutanol + c18 stearate; liquid emollient (branching prevents crystallization); non-greasy, good spreading; suitable for lightweight skin care.
Last Verified: 2026-03-28
Primary Sources: Cosing database,inci dictionary