Body & Beauty / Compounds / Butylene glycol

Butylene glycol on your skin: a safety profile

Low risk

(People-specific data is limited; this page draws from human adult context.) Safety profile for Butylene glycol relevant to people.

What is butylene glycol?

The IUPAC name is 1,3-butanediol.

Also known as: 1,3-butanediol, BG, 1,3-butylene glycol, methyl ethyl glycol.

IUPAC name
1,3-butanediol
CAS number
107-88-0
Molecular formula
C4H10O2
Molecular weight
90.12 g/mol
SMILES
CC(CCO)O
PubChem CID
7896

Risk for people

Low risk

Regulatory consensus

3 regulatory and scientific bodies have classified Butylene glycol. The classifications differ — that's the data.

AgencyYearClassificationNotes
EU_CLP—Acute Tox. 4 (Oral)H302: Harmful if swallowed
EPA——Approved as cosmetic ingredient; generally recognized as safe (GRAS) status in food applications
FDA——Approved for use in cosmetics and over-the-counter drug products

Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.

Where you encounter butylene glycol

  • cosmetics
  • skincare products
  • haircare products
  • antifreeze
  • thermoelectric coolants

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Butylene glycol:

  • Glycerin (plant-derived) — gold standard humectant, excellent safety profile
    Trade-offs: Consumer preference for 'natural' label; many natural fragrance compounds are potent allergens (limonene, linalool, eugenol); 'natural' ≠ 'safe'; often more expensive than synthetic equivalents.
    Relative cost: 2-5× conventional
  • Hyaluronic acid — naturally occurring, very low sensitization potential
    Trade-offs: Removes 95-99% of dissolved contaminants including metals, PFAS, nitrates; wastes 2-4 gallons per gallon produced (improving with newer systems); removes beneficial minerals; $0.05-0.25/gallon; requires pre-treatment for longevity.
    Relative cost: 2-5× conventional
  • Panthenol (provitamin B5) — well-tolerated, additional skin-soothing properties
    Trade-offs: Removes 95-99% of dissolved contaminants including metals, PFAS, nitrates; wastes 2-4 gallons per gallon produced (improving with newer systems); removes beneficial minerals; $0.05-0.25/gallon; requires pre-treatment for longevity.
    Relative cost: 1.2-2×

Frequently asked questions

What products contain butylene glycol?

Butylene glycol appears in: cosmetics; skincare products; haircare products.

Why do regulators disagree about butylene glycol?

Butylene glycol has been classified by 3 agencies including EU_CLP, EPA, FDA, with differing conclusions. Regulators apply different standards of evidence (animal data weighting, exposure-pattern assumptions, epidemiological power thresholds), which is why two scientific bodies can review the same data and reach different conclusions. See the regulatory consensus table on this page for the full picture.

See Butylene glycol in the body app

Look up products containing butylene glycol, compare to alternatives, and explore the full data record.

Open in body View raw API data

Sources (2)
  1. PubChem Compound CID 7896 — database
  2. ATSDR Toxicological Profile — CAS 107-88-0 — reference

Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →