Ingredient Intelligence
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Propanediol

A bio-fermented multi-functional humectant and solvent. A more sustainable alternative to petroleum-derived propylene glycol, widely adopted in clean K-beauty and prestige formulations.

Benefits
  • Humectant — water binding in stratum corneum
  • Solvent — dissolves hydrophilic actives
  • Penetration enhancer at higher concentrations
  • Bio-derived (from corn sugars via fermentation)
  • COSMOS-certified
Example uses
  • K-beauty toners and essences
  • SPF sun serums
  • Foundation vehicles
  • Brightening serums
  • Gel moisturisers
Mechanism of action
Short-chain diol binds water via hydroxyl group hydrogen bonding, reducing TEWL. Reduces activity coefficient of co-dissolved actives, improving their skin penetration via the aqueous pathway. Bio-fermentation origin (from Dupont/Ingeo or equivalent corn-to-propanediol process) produces functionally identical material to petrochemical propanediol.
Clinical evidence · High

Safety extensively characterised. SCCS assessment completed. Functional equivalence to propylene glycol confirmed. Bio-derived certification supported by Dupont Tate and Lyle fermentation process.

Effective concentration range
1–10% (humectant); q.s. (solvent)
Formulation notes
Bio-derived from corn sugar fermentation. Water-soluble; miscible across all cosmetic pH. Effective humectant at 3–10%. Compatible with virtually all cosmetic ingredients.
Watchouts
At very high concentrations (>20%) can cause temporary irritation. At typical cosmetic use levels (1–10%), no established safety concern. Corn-derived — GMO sourcing question for strict natural consumers.
Controversies & overclaims
The bio-derived framing is accurate for commercially certified Zemea propanediol and equivalent products. Unverified bio-derived claims from other suppliers should be scrutinised for certification documentation.
Market positioning
Marketed as clean-beauty alternative to propylene glycol. Functionally accurate; bio-derived origin fully supported by fermentation certification.
Comedogenicity

0 / 5

Sensitisation risk

Low

INCI & aliases

Propanediol

1,3-propanediol · trimethylene glycol · propylene glycol analogue

Clean beauty perception

Strongly accepted in clean beauty due to bio-derived fermentation origin and COSMOS certification. Commonly positioned as the clean-beauty alternative to propylene glycol.

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