2-Bromo-2-Nitropropane-1,3-Diol

2-Bromo-2-Nitropropane-1,3-Diol 1
molecular structure · PubChem CID 2450
AKA: Bronopol, 52-51-7, 2-Bromo-2-nitro-1, 3-propanediol, Bronosol, Bronocot, Bronotak, Bronidiol, Bronopolu, Lexgard bronopol
Synthetic
Preservative
Not Clean
OriginSynthesized from brominated nitro compounds within the halogenated organic chemical family. Produced through bromination and nitration reactions of propane-1,3-diol derivatives.
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
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
Fights Bacteria
Locks In Moisture
Wound Healing
Prevents microbial growth
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
7
CIR
Safe as used · CIR tentative re-review report (2026)
Pregnancy
Caution
CIR Safety Findings
Mixed Eye Irritation Results
7 studies / 4 irritating / 2 mixed / 1 not irritating / reactions severe (CIR 920)
Mixed Skin Irritation Results
13 studies / 6 irritating / 4 mixed / 3 not irritating / reactions slight to severe / plus 4 case reports (CIR 208 and 249 and 920)
Mixed Sensitization Results
9 studies / 2 sensitizing / 1 mixed / 6 not sensitizing / plus 14 case reports (CIR 208 and 249 and 920)
Dermal Absorption 11–24%
rats and rabbits / in vivo / aqueous solution 4 mg/ml applied to skin / 24 h (CIR 920)
Concentration Guide
Leave-on0.001–0.05%
Rinse-off0.00045–0.05%
0%50%100%
Reg. limit 0.1%
CIR reported use · 2025 survey
EU regulatory limit: 0.1%. Source: EU Cosmetics Regulation (EC) 1223/2009, Annex V (Preservatives), Entry 21.
Regulatory Status
USAunder review
EU✔ permitted
JAPAN✔ permitted
CANADA✔ permitted
🧂Conflict of interest.
Verified Jun 2026 · 🧪 = conflict
Data: PubChem · CosIng · EWG · CIR