Caprylyl Glycol
Also known as 1,2-Octanediol, Octane-1,2-diol, Caprylic glycol, Dermosoft Octiol
“CIR Expert Panel says: safe as used in cosmetics.”
Caprylyl Glycol (1,2-octanediol; CAS 1117-86-8; C8H18O2) is a C8 alkane-1,2-diol used in cosmetic formulations as a preservative booster, humectant, and skin conditioning agent. Like ethylhexylglycerin, it is frequently paired with phenoxyethanol and other preservatives to enhance antimicrobial efficacy and enable lower total preservative loads. The Cosmetic Ingredient Review Expert Panel reviewed caprylyl glycol together with 15 other 1,2-alkane-diols — including pentylene glycol, 1,2-hexanediol, and C15-18 glycol — and concluded they are safe in the present practices of use and concentration (Johnson, Bergfeld, Belsito et al., Int J Toxicol 31(5 Suppl):147S-168S, 2012, PMID 23064773). The Panel noted that while 1,2-glycols are dermally absorbed, modeling predicted decreased skin penetration for longer-chain members of the series; combined with negative oral toxicity and genotoxicity data on the shorter-chain 1,2-glycols, this supports the safety conclusion. The QRT row carries no conditions or concentration limits.
Preservative booster that enhances phenoxyethanol and organic-acid preservative efficacy, enabling lower total preservative concentrations
Humectant and skin conditioning agent with good skin compatibility at typical use levels (0.3-1.0%)
CIR Expert Panel concluded safe as used in cosmetics (Johnson et al., IJT 2012, PMID 23064773) — same assessment also clears pentylene glycol, 1,2-hexanediol, and C15-18 glycol
Skin penetration decreases with increasing alkyl chain length in the 1,2-glycol series, giving caprylyl glycol a more favorable dermal profile than the shorter butylene glycol or ethoxydiglycol
- · Occasional contact allergy reports exist in the dermatology literature but at low prevalence; caprylyl glycol is generally considered a mild sensitizer comparable to other preservative boosters
As a small aliphatic diol, caprylyl glycol is dermally absorbed; the CIR 2012 assessment relied on predictive modeling and oral toxicity data on shorter-chain homologues rather than dedicated dermal absorption studies on caprylyl glycol itself
CIR Quick Reference Table (12/2017, revised 07/2018) - Caprylyl Glycol row: Finding 'S' (Safe), Citation 'IJT 31(S2):147-168, 2012'
“Caprylyl Glycol | S | [no detail column entry] | IJT 31 (S2): 147-168, 2012”— QRT-122017revised072018.pdf, p. 21