Dimethiconol
Also known as Dimethylsilanol, Hydroxy-terminated polydimethylsiloxane, Silicone diol
“CIR Expert Panel says: safe as used in cosmetics.”
Dimethiconol (CAS 70131-67-8) is a hydroxy-terminated polydimethylsiloxane used as a skin and hair conditioning agent and emollient. The CIR Expert Panel completed a dedicated safety assessment in 2017 (IJT 36(Suppl. 3):31-50) covering dimethiconol and its esters and reaction products, concluding these ingredients are safe as used in cosmetics. The Panel cited negligible dermal absorption as the primary rationale for ruling out systemic reproductive, developmental, and carcinogenic risk, consistent with the broader linear silicone safety profile.
Provides skin and hair conditioning; imparts smoothness and slip at typical cosmetic use levels
Hydroxyl end-groups enable reactivity with hair proteins, improving substantivity relative to dimethicone
CIR Expert Panel found safe as used in cosmetics based on negligible percutaneous absorption:31-50, 2017)
Chemically inert polysiloxane backbone; does not react with skin components
CIR Quick Reference Table (12/2017, revised 07/2018) — Dimethiconol row: Finding=S, Citation=IJT 36(Suppl. 3):31-50, 2017
“Dimethiconol | S | | IJT 36(Suppl. 3):31-50, 2017”— QRT-122017revised072018.pdf, p. 45