murphyIodopropynyl Butylcarbamate
AKA: 55406-53-6, 3-Iodo-2-propynyl butylcarbamate, Ipbc, Woodlife, Troysan KK-108A, 3-IODO-2-PROPYNYLBUTYLCARBAMATE, Caswell No. 501A, 3-iodoprop-2-yn-1-yl N-butylcarbamate, Butyl-3-iodo-2-propynylcarbamate
Synthetic
Preservative
Not Clean
Iodopropynyl Butylcarbamate (IPBC) is a cosmetic ingredient used as preservative. Assessed as safe by the CIR. 3-Iodo-2-propynyl butylcarbamate
Solubility In water, 156 mg/L at 20 °C
Formula
C8H12INO2
Mol. Weight
281.09
CAS #
55406-53-6
Form
Powder
State
3-iodo-2-propynyl butylcarbamate is an off-white solid.
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Caution
Functions
Preservative
Keeps your product from growing bacteria, mold, or yeast. Without these, that jar of cream becomes a petri dish in about a week.
Preserves Formula
Antioxidant Protection
Reduces Inflammation
Locks In Moisture
Prevents microbial growth
The paper trail
🔬Peer-reviewed2 papers →
⚖️Regulatory2 listings →
🛡️Safety-assessed2 reviews →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
EWG
6
CIR
Safe as used
Pregnancy
Caution
CIR Safety Findings
Not a Sensitizer
5 studies / 5 not sensitizing (CIR 43)
Not Phototoxic
Animal test and Product formulation test found no phototoxicity in the CIR safety assessment (CIR 43)
Mixed Eye Irritation Results
5 studies / 3 irritating / 1 mixed / 1 not irritating / reactions slight to severe (CIR 43)
Mixed Skin Irritation Results
12 studies / 5 irritating / 2 mixed / 5 not irritating / reactions slight to severe (CIR 43)
Mixed Comedogenicity Results
Both comedogenic and non-comedogenic results in the CIR safety assessment (CIR 43)
Dermal Absorption 53%
human cadaver skin (epidermis and papillary dermis) in vitro / 5 microliters of 0.1% radioactive IPBC in acetone / 24 hours (CIR 43)
Concentration Guide
Leave-on0.001–0.05%
Rinse-off0.00012–0.05%
0%50%100%
Reg. limit 0.02%
CIR reported use · 2013 survey
EU regulatory limit: 0.02%. a) 0.02% b) 0.01% c) 0.0075%. a) Not to be used for children under three years of age (11) b) and c) Not to be used for children under three years of age (12) Source: EU Cosmetics Regulation (EC) 1223/2009, Annex V (Preservatives), Entry 56.
Regulatory Agencies
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR