Benzethonium Chloride
AKA “121-54-0, Hyamine, Phemeride, Phemerol Chloride, Benzethoniumchloride, Quatrachlor, Disilyn, Kylacol, Phemithyn
Preservative
Ingredient Facts
Benzethonium chloride
AKA: 121-54-0, Hyamine, Phemeride, Phemerol Chloride, Benzethoniumchloride, Quatrachlor, Disilyn, Kylacol, Phemithyn
Preservative · Antimicrobial · EWG: 4
Synthetic
Preservative
Cleanser
Not Clean
Benzenemethanaminium, N,N-dimethyl-N-[2-[2-[4-(1,1,3,3,-tetramethylbutyl)phenoxy]ethoxy]ethyl]-, chloride
Solubility 10 to 50 mg/mL at 64 °F (NTP, 1992)
Formula
C27H42ClNO2
Mol. Weight
448.10
CAS #
121-54-0
Form
Liquid
State
Benzethonium chloride appears as odorless white crystals or powder with a very bitter taste. A 1% solution in water is slightly alkaline to litmus. (NTP, 1992)
See origin →
Functions
Antimicrobial
Keeps your product from growing bacteria, mold, or yeast. Without these, that jar of cream becomes a petri dish in about a week.
Deodorant
Preservative
Keeps your product from growing bacteria, mold, or yeast. Without these, that jar of cream becomes a petri dish in about a week.
Dispersing
Fights Bacteria
Traditional Use
A quaternary ammonium preservative developed in the mid-20th century as an antimicrobial and preservative agent. Created as an alternative to benzalkonium chloride with claimed superior stability in certain cosmetic formulations.
Skin Types
all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Caution
EWG
4
CIR
Safe as used
Pregnancy
Caution
CIR Safety Findings
Not a Sensitizer
ewg-4
medical-approval
all-shades-safe
Concentration Guide
0.1%
0%0%
Reg. Limit
EU regulatory limit: 0.1%. Source: EU Cosmetics Regulation (EC) 1223/2009, Annex V (Preservatives), Entry 53.
Regulatory Status
USApermitted
EUpermitted
JAPANpermitted
CANADApermitted
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR