Phenyl Trimethicone

Phenyl Trimethicone 1
molecular structure · PubChem CID 62427
AKA: 1, 5, 5-Hexamethyl-3-phenyl-3-(trimethylsilyloxy)trisiloxane, 2116-84-9, Phenyltris(trimethylsiloxy)silane, 5-hexamethyl-3-phenyl-3-((trimethylsilyl)oxy)trisiloxane, Tris(trimethylsiloxy)phenylsilane, Trimethyl-[phenyl-bis(trimethylsilyloxy)silyl]oxysilane
Synthetic
Skin Conditioner
Hair Care
Clean
OriginDerived from siloxane compounds, a class of synthetic polymers containing silicon-oxygen bonds. Synthesized through hydrosilylation reactions that bond phenyl groups to polydimethylsiloxane backbone structures.
1,1,5,5,5-Hexamethyl-3-phenyl-3-[(trimethylsilyl)oxy]trisiloxane
Formula
C15H32O3Si4
Mol. Weight
372.75
CAS #
2116-84-9
Form
Liquid
State
Liquid
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Yes
Functions
Antifoaming
Hair Conditioning
A catch-all term for ingredients that improve how skin looks and feels — softer, smoother, more supple. The workhorse behind most moisturizers.
Skin Conditioning
A catch-all term for ingredients that improve how skin looks and feels — softer, smoother, more supple. The workhorse behind most moisturizers.
Locks in moisture
The paper trail
🔬Peer-reviewed1 paper →
⚖️Regulatory1 listing →
🛡️Safety-assessed3 reviews →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
EWG
1
CIR
Safe with qualifications (safe as used, but data insufficient for products that may be incidentally inhaled)
Pregnancy
Yes
CIR Safety Findings
Not Phototoxic
Human test found no phototoxicity in the CIR safety assessment (CIR 847)
Not a Sensitizer
6 studies / 6 not sensitizing / plus 1 case report (CIR 172 and 847)
Mixed Eye Irritation Results
5 studies / 1 irritating / 4 not irritating / reactions slight (CIR 172 and 847)
Mixed Skin Irritation Results
13 studies / 4 irritating / 1 mixed / 8 not irritating / reactions minimal to mild (CIR 172 and 847)
Concentration Guide
Leave-on0.1–24.8%
Rinse-off0.75–59.5%
0%50%100%
CIR reported use · 2022 survey
Regulatory Status
USA✔ permitted
EU⚠ restricted
JAPAN⚠ restricted
CANADA⚠ restricted
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR