2-Bromo-2-Nitropropane-1,3-Diol
molecular structure · PubChem
AKA: Bronopol, 52-51-7, 2-Bromo-2-nitro-1, 3-propanediol, Bronosol, Bronocot, Bronotak, Bronidiol, Bronopolu, Lexgard bronopol
Synthetic
Preservative
Not Clean
1,3-Propanediol, 2-bromo-2-nitro-
Solubility greater than or equal to 100 mg/mL at 63 °F (NTP, 1992)
Formula
C3H6BrNO4
Mol. Weight
199.99
CAS #
52-51-7
Form
Powder
State
2-bromo-2-nitropropane-1,3-diol appears as white crystals. Ignite easily and burn readily. May detonate under strong shock. Decomposes when heated, evolving toxic gases. Toxic by skin absorption, inha
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
Fights Bacteria
Locks In Moisture
Wound Healing
Prevents microbial growth
Traditional Use
A synthetic preservative developed in the mid-20th century for cosmetics and personal care products. It was designed to provide broad-spectrum antimicrobial activity and replace older, less effective preservatives.
EWG
7
CIR
Safe as used
Pregnancy
Caution
Restricted By
CIR Safety Findings
Not a Sensitizer
ewg-7
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 21.
Regulatory Agencies
🧂Conflict of interest.
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Caution
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.
Verified Jun 2026 · 🧪 = conflict
Data: PubChem · CosIng · EWG · CIR