3-Butylene glycol (butylene glycol) is a small diol commonly used in skincare as a humectant, solvent, and viscosity-reducing agent. It helps attract moisture, dissolve other ingredients, and improve product texture and preservation.
| Reported effect | How often | Notes |
|---|---|---|
Mild skin irritation or stinging | Uncommon | Usually transient, more likely on compromised or sensitive skin or at high concentrations. |
Allergic contact dermatitis | Rare | Documented in patch-test case reports; considered a low-frequency sensitizer. |
Eye irritation | Uncommon | Can occur with direct contact in eye-area products. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.