What it is
A small-molecule diol, clear liquid used as solvent and humectant.
What it does
Improves feel, enhances ingredient penetration, adds humectancy.
Why it’s a concern
Lower sensitisation rate than propylene glycol but still capable of enhancing penetration of other ingredients, which can amplify problems if the formula contains other concerning compounds. Low acute toxicity.
Also known as
1,3-butanediol
CAS numbers
107-88-0
Commonly found in
serummoisturisertoner
Safer alternatives
- vegetable glycerin
- 1,3-propanediol from corn
Sources
- CIR Final Report on Butylene Glycol