humectant · solvent
Butylene Glycol
Fearmongered, actually fine·Strong evidence
A lightweight humectant and solvent similar in role to propylene glycol, used to carry actives and give lotions a lighter feel. CIR has reviewed it and considers it safe as used in cosmetics.
The myth vs the evidence
It sometimes gets swept into the same "glycol = petrochemical toxin" fear as propylene glycol. The evidence does not support meaningful risk at cosmetic use levels; irritation is uncommon and mainly seen in leave-on products at higher concentrations on already-compromised skin.
Products with Butylene Glycol
References
Cosmetic information for general education, not medical advice. Concern is graded on cited evidence, never on hazard-score lists. See how we score.