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2-BROMO-2-NITROPROPANE-1,3-DIOL.

Valuable CAS 52-51-7 / PRESERVATIVE

A dual-action antimicrobial preservative that protects skincare formulations through both direct bacterial inhibition and controlled formaldehyde release. This water-soluble ingredient disrupts microbial metabolism by targeting essential thiol groups in bacterial cells while maintaining product integrity across various pH ranges.

preservative antimicrobial

Science

Functions as a broad-spectrum antimicrobial through two pathways: catalyzing oxidation of essential thiol groups like cysteine in bacterial cells to form disulfides under aerobic conditions, and releasing formaldehyde that denatures microbial proteins and nucleic acids, collectively disrupting bacterial metabolic processes


Research

High confidence
Effective range 0.05–0.1%
Optimal

0.05%

Key findings

  1. 01 Large European multicenter study (8,149 patients) demonstrated 0.47% allergic reaction rate and 0.12% irritation rate at 0.5% concentration
  2. 02 Patch testing study (149 subjects) at 0.25% showed only 2% transient erythema with no sensitization evidence
  3. 03 Animal studies confirmed no irritation at 0.5% with repeated application versus severe irritation at 2.0%

Transparency

Not commonly dusted

As a preservative with established safety limits, dusting is not applicable - effectiveness requires minimum concentrations for antimicrobial function


The Formula

Solubility
Water
Optimal pH 5 – 8.8
0 7 14

Stability

Exhibits high stability in acidic conditions but becomes unstable in alkaline environments and temperatures exceeding 45°C, where decomposition accelerates formaldehyde release

Conflicts

  • Secondary amines (Diethanolamine, Triethanolamine)
  • Amides
  • Strongly alkaline environments
  • High temperatures above 45°C

Safety

CIR Status
Safe with restrictions
Max tested
0.1%
Sensitization risk Low

Current industry usage has decreased to 0.05% as of 2023-2025 surveys; must avoid formulation with secondary amines or amides to prevent nitrosamine formation


Your Skin

Yes Normal
Yes Dry
Yes Oily
No Sensitive
Irritancy Moderate
Comedogenicity Low

Our Assessment

Valuable

An effective broad-spectrum preservative with well-established safety data, suitable for most skin types when used within regulatory limits and proper formulation parameters.


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