murphyUndecylenic Acid
AKA: Undec-10-enoic acid, 10-UNDECENOIC ACID, 112-38-9, 10-Hendecenoic acid, Renselin, Declid, Sevinon, 10-Undecylenic acid, Undecylenate
Synthetic
Preservative
Cleanser
Emulsifier
Acid
Clean
Undec-10-enoic acid; 10-Undecenoic acid
Solubility Insoluble
Formula
C11H20O2
Mol. Weight
184.27
CAS #
112-38-9
Form
Liquid
State
Liquid
Skin Types
●all-skin-types
Best For
Acne
Pregnancy & Breastfeeding Safe
Caution
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.
Preservative
Keeps your product from growing bacteria, mold, or yeast. Without these, that jar of cream becomes a petri dish in about a week.
Cleansing
Makes oil and water mix so dirt, makeup, and sunscreen can actually be washed away. The reason your face wash foams.
Emulsifying
Forces oil and water to stay mixed instead of separating into layers. The unsung hero holding your lotion together.
Fights Bacteria
The paper trail
🔬Peer-reviewed1 paper →
⚖️Regulatory1 listing →
🛡️Safety-assessed2 reviews →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
EWG
2
CIR
Safe as used
Pregnancy
Caution
CIR Safety Findings
Skin Irritant in Testing
1 study / 1 irritating (CIR 777)
Mixed Sensitization Results
3 studies / 1 sensitizing / 2 not sensitizing / plus 1 case report (CIR 777)
Eye Irritant in Testing
1 study / 1 irritating / reactions mild to moderate (CIR 777)
Concentration Guide
Leave-on0.2–25%
Rinse-offNot reported
0%50%100%
Reg. limit 0.2%
CIR reported use · report published 2019
EU regulatory limit: 0.2%. Source: EU Cosmetics Regulation (EC) 1223/2009, Annex V (Preservatives), Entry 18.
Regulatory Agencies
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR