Bronopol (CAS 52-51-7): Safety, Stability, and Formulation Considerations
Bronopol, known by its CAS number 52-51-7, is a highly effective antimicrobial agent, but like all chemical compounds, understanding its safety, stability, and formulation intricacies is paramount for its optimal and safe use. NINGBO INNO PHARMCHEM CO.,LTD. emphasizes the importance of adhering to best practices when incorporating Bronopol into various products, ensuring both efficacy and user safety.
The safety profile of Bronopol is generally favorable when used at recommended concentrations. While it is an antimicrobial agent, concerns regarding its potential to release formaldehyde and its interaction with secondary amines to form nitrosamines have led to careful regulatory scrutiny and formulation guidance. Bronopol itself is considered an irritant to eyes and skin, and has moderate toxicity via ingestion and dermal absorption. However, at the typical low in-use concentrations of 0.03-0.1%, it is generally regarded as safe for many applications, including cosmetics, provided proper formulation controls are in place. For example, incorporating antioxidants can mitigate nitrosamine formation.
Regarding chemical stability, Bronopol exhibits good performance under acidic conditions. However, its stability significantly decreases in alkaline environments (high pH) and at elevated temperatures. Under such conditions, it can decompose, liberating nitrite ions and formaldehyde, and potentially reacting with secondary amines or amides to form nitrosamines, which are carcinogenic. Therefore, formulators must carefully control the pH of their systems and avoid incompatible ingredients. Bronopol is also known to be incompatible with strong bases, oxidizing agents, and aluminum, so packaging and formulation choices are critical.
When developing formulations with Bronopol, several key considerations are advised. For products that require Bronopol to be added to the aqueous phase, it is recommended to do so early in the formulation process to prevent initial bacterial growth in that medium. If the control of yeasts and molds is a primary concern, Bronopol can be effectively combined with other antimicrobials that offer enhanced anti-fungicidal activity. Blends of Bronopol with parabens, for instance, provide comprehensive coverage across the microbial spectrum. Its high compatibility with a wide range of surfactants (cationic, nonionic, anionic, and amphoteric) and other raw materials makes it a versatile preservative.
The decomposition products of Bronopol, such as bromonitroethanol and formaldehyde, while contributing to its antimicrobial action, also necessitate careful handling and formulation. While formaldehyde is released in low concentrations, its potential for sensitization means that avoiding secondary amines in formulations containing Bronopol is a key recommendation. Manufacturers often opt to use nitrosamine inhibitors or reformulate to exclude amines altogether when using Bronopol to ensure product safety.
At NINGBO INNO PHARMCHEM CO.,LTD., we provide Bronopol that meets stringent quality standards. Understanding and implementing these safety, stability, and formulation guidelines is essential for harnessing the full potential of Bronopol as an effective antimicrobial while ensuring the safety and integrity of your final products. Consulting with our technical experts can provide further guidance on the best practices for your specific application.
Perspectives & Insights
Nano Explorer 01
“Blends of Bronopol with parabens, for instance, provide comprehensive coverage across the microbial spectrum.”
Data Catalyst One
“Its high compatibility with a wide range of surfactants (cationic, nonionic, anionic, and amphoteric) and other raw materials makes it a versatile preservative.”
Chem Thinker Labs
“The decomposition products of Bronopol, such as bromonitroethanol and formaldehyde, while contributing to its antimicrobial action, also necessitate careful handling and formulation.”