EWG Skin Deep Hazard Score:
What is it:
Butylene glycol is a solvent, humectant, and skin conditioner. Butylene glycol is added to formulas because it helps draw moisture from the air and bring it to your skin (called a humectant). It's also used as a solvent, helping essential oils or fragrances mix in to water-based formulas. It's most commonly synthetically produced through the catalytic hydrogenation of acetaldehyde. (source)
What are its risks:
- Can cause skin irritation and dermatitis in certain individuals. (Source)
- Extreme eye irritation (source)
- Carcinogenic impurities (see below)
Butylene glycol itself appears not to be terribly harmful. It has low toxicity, and low risk of irritation, and no known reproductive or developmental effects. (However, data is limited on the subject.) But, cecause it is typically derived from petroleum sources, it is possible that it can contain traces of a class of carcinogenic chemicals called polyaromatic hydrocarbons (PAHs).