Steartrimonium Chloride

AKA: 112-03-8, Trimethylstearylammonium chloride, Stac, Cation AB, Aliquat 7, Stearyltrimethylammonium chloride, Nissan cation AB, Quaternium-10, Arquad 18, Stearyl trimethyl ammonium chloride
Plant-Derived
Preservative
Skin Conditioner
Hair Care
Plant Oil
Not Clean
Trimethyloctadecylammonium chloride
Formula
C21H46ClN
Mol. Weight
348.00
CAS #
112-03-8
Form
Liquid
Functions
Antistatic
Hair Conditioning
A catch-all term for ingredients that improve how skin looks and feels — softer, smoother, more supple. The workhorse behind most moisturizers.
Preservative
Keeps your product from growing bacteria, mold, or yeast. Without these, that jar of cream becomes a petri dish in about a week.
Reduces Static
Conditions Hair
Preserves Formula
Reduces flyaways
Softens and detangles hair
Prevents microbial growth
Traditional Use
Synthesized as a quaternary ammonium salt in mid-20th century cosmetic chemistry. Developed as a cationic conditioning agent for hair and skin products to improve texture and manageability.
EWG
7
CIR
Safe as used
Pregnancy
Yes
CIR Safety Findings
Not a Sensitizer
medical-approval
all-shades-safe
Regulatory Status
USApermitted
EUpermitted
JAPANpermitted
CANADApermitted
🧂Conflict of interest.
Skin Types
all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Yes
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.
Verified Jun 2026 · 🧪 = conflict
Data: PubChem · CosIng · EWG · CIR