Pentylene glycol on your skin: a safety profile

What is pentylene glycol?

The IUPAC name is 1,2-pentanediol.

Also known as: 1,2-pentanediol, pentane-1,2-diol, methyl propyl glycol, Menthoglycol.

IUPAC name

1,2-pentanediol

CAS number

5343-92-0

Molecular formula

C5H12O2

Molecular weight

104.15 g/mol

SMILES

CC1CCC(C(C1)O)C(C)(C)O

PubChem CID

19100

Regulatory consensus

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

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 pentylene glycol

• cosmetics
• skincare formulations
• preservative systems
• personal care products

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Pentylene 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