2,3-Butanediol
molecular structure · PubChem
AKA: 513-85-9, Butane-2, 3-diol, 3-butylene glycol, 3-Dihydroxybutane, Dimethylethylene glycol, Pseudobutylene glycol, Sym-dimethylethylene glycol
Synthetic
Humectant
Solvent
Skin Conditioner
Clean
The Panel also concluded that the available data are insufficient to make a determination that ... 2,3-Butanediol ... is safe under the intended conditions of use in cosmetic formulations.
Solubility In water, miscible at 20 °C
Formula
C4H10O2
Mol. Weight
90.12
CAS #
513-85-9, 5341-95-7, 24347-58-8
Form
Liquid
State
Liquid
Functions
Humectant
A moisture magnet. Pulls water from the air and deeper skin layers up to the surface to keep skin plump and hydrated.
Skin Conditioning
A catch-all term for ingredients that improve how skin looks and feels — softer, smoother, more supple. The workhorse behind most moisturizers.
Solvent
Dissolves other ingredients so they distribute evenly in the formula. Often the invisible "base" everything else is mixed into.
Locks In Moisture
Traditional Use
A synthetic humectant developed in the mid-20th century for use in cosmetics and pharmaceuticals. It was created to provide moisture-binding properties similar to glycerin but with different viscosity characteristics.
EWG
1
CIR
Safe as used
Pregnancy
Yes
Restricted By
CIR Safety Findings
ewg-1
medical-approval
pregnancy-nursing-safe
all-shades-safe
Moderate Irritant
Regulatory Agencies
Skin Types
●all-skin-types, gentle
Best For
Dehydration
Pregnancy & Breastfeeding Safe
Yes
The paper trail
🔬Peer-reviewed1 paper →
⚖️Regulatory1 listing →
🛡️Safety-assessed2 reviews →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR