Toward the future of OECD/ISO biodegradability testing-new approaches and developments

Area of Science:

• Environmental chemistry
• Microbiology
• Chemical risk assessment

Background:

• Standardized biodegradability tests (OECD, ISO, CEN) are integrated into regulations like REACH.
• Current tests have deficiencies in accurately reflecting real-world environmental conditions.
• Predicting biodegradability from chemical structures and complex mixtures remains a challenge.

Purpose of the Study:

• To critically evaluate the technical strengths and weaknesses of current biodegradability testing systems.
• To explore enhanced prediction possibilities using combined test systems and in silico models.
• To propose a new concept for assessing inoculum biodegradation adaptation potential (BAP).

Main Methods:

• Review of technical aspects of OECD/ISO biodegradability tests, including setup and inoculum characterization.
• Analysis of combined test systems and in silico quantitative structure-activity relationship (QSAR) models.
• Discussion on the biodegradation of challenging single compounds and chemical mixtures (UVCBs).

Main Results:

• Current biodegradability tests require technical improvements for better environmental relevance.
• Inoculum characterization and its biodegradation potential are critical factors.
• Combined test systems and QSAR models offer enhanced predictive capabilities.

Conclusions:

• Improvements in biodegradability test design and inoculum assessment are crucial.
• Combined approaches and in silico methods can enhance environmental predictions.
• Addressing the biodegradation of complex chemical mixtures is a key future challenge.