The EU evaluation of alternatives to 3-iodo-2-propynylbutylcarbamate (IPBC), a fungicidal biocide widely used for preserving construction materials, has revealed significant technical and regulatory obstacles. While alternatives such as Fludioxonil and Pythium oligandrum were assessed, neither meets the broad efficacy and usability of IPBC under current Biocidal Products Regulation (BPR) requirements.
IPBC’s Role and Regulatory Challenges
IPBC is a crucial component in construction material preservatives under Product Type (PT) 10, protecting non-wood materials from fungal damage. However, its potential classification as an environmental endocrine disruptor under BPR’s substitution criteria has prompted an in-depth analysis of alternatives.
Evaluated Alternatives
The analysis identified two main candidates:
- Fludioxonil: A chemical fungicide with limited application to indoor use. Despite its technical feasibility in some scenarios, it lacks authorization for outdoor uses and availability in approved biocidal products.
- Pythium oligandrum: A biological alternative suitable for indoor applications using waterborne formulations. However, its limited spectrum of efficacy and inability to serve in solvent-based or outdoor formulations restrict its viability.
Challenges with Alternatives
Both alternatives fall short in addressing the comprehensive demands of construction material preservation, including efficacy, formulation compatibility, and market availability. Fludioxonil’s classification as a potential per- and polyfluoroalkyl substance (PFAS) also raises concerns over future regulatory restrictions.
Economic and Technical Constraints
Developing new biocidal substances faces prohibitive costs, averaging €10 million over a 10-year timeline. This deters innovation, leaving the industry dependent on existing substances that meet stringent BPR criteria.
The absence of viable alternatives underscores IPBC’s critical role in PT 10 applications. The report advocates maintaining IPBC’s availability while exploring long-term innovations to meet environmental and safety standards.
