Tag Archive for: persistence

Report published on further development of screening tests for the evaluation of potential PBT substances

Different ready biodegradability tests (OECD 301 series and OECD 310) are currently used for evaluating if a substance is readily biodegradable and for identifying potentially persistent substances. Although the methods differ considerably, the test results are considered equivalent. In persistency assessments under REACH, enhanced ready biodegradability tests with an extended test duration (up to 60 […]

Publication on validation of a method to determine transformation of chemicals in manure

Manure is widely used as a fertilizer and applied to agricultural land. It may contain highly active chemicals like veterinary medicinal products or biocides, which enter the environment by this pathway. This is recognized by several regulatory frameworks, however, a detailed method for examining the transformation of chemicals in manure was lacking. The present publication […]

Critical review and proposal for multigenerational testing in standard soil invertebrates

Standard laboratory tests to evaluate the effects of stressors (in most cases chemicals) on soil organisms offer a good compromise between feasibility and outcome, i.e. they should be reproducible and provide robust results. However, these tests may underestimate potential effects of prolonged exposures, particularly for persistent contaminants. In the last years, there was an increase […]

New test guideline: Anaerobic transformation of chemicals in liquid manure

New test guideline: Anaerobic transformation of chemicals in liquid manure

On 30 June 2022, the OECD published test guideline No. 320: ‘Determining anaerobic transformation of chemicals in liquid manure’. This guideline describes a standardised method to investigate transformation of chemical substances in pig and cattle liquid manure under anaerobic conditions. The experiments are performed to determine the rate of transformation of the test substance, the […]

Publication on enhanced ready biodegradability screening tests

In persistence assessment, enhanced ready biodegradability tests (eRBT) are used to close the gap between screening tests and complex simulation tests. However, only few data from such tests are available, and neither guidance on the design and interpretation of eRBTs, nor suitable validity criteria have been established so far. In a practical testing programme, five […]

New publication: Compartment‐specific screening tools for persistence – potential role and application in the regulatory context

The persistence assessment under REACH relies on compartment‐specific degradation half‐lives derived from laboratory simulation studies with surface water, aquatic sediment or soil. Although these data are given priority, they are not available for most of the compounds. Therefore, according to the integrated assessment and testing strategy for persistence assessment, results from ready biodegradability tests are […]

Further development of simple test systems for the evaluation of potential PBT substances: How to bridge the gap between screening tests and complex studies?

The first aim of the project was to assess whether the existing OECD test guidelines for ready biodegradability of chemicals (OECD test guidelines 301 A–D and 310) can be harmonized. The gained insights were discussed at an international expert workshop in April 2019. Laboratory experiments were performed for five test substances to verify the impact […]

Report on assessment of environmental persistence

Report published on ‘Assessment of environmental persistence’

A literature study was performed to review the applicability of established and new tests for biodegradability for assessing persistence in the frame of PBT and vPvB assessments under REACH. Screening tests for ready and inherent biodegradability, proposals for enhanced ready tests as well as newly designed compartment-specific screening tests were analysed for strengths and weaknesses, […]

Improved strategy to assess chemical persistence at the water-sediment interface

The environmental fate of a compound is determined by transformation and distribution processes, which are strongly dependent on the specific environmental conditions. Biodegradability of chemicals in different environmental compartments is one of the major determinants of their environmental fate and therefore plays a crucial role in regulatory decision-making. Simulation studies according to OECD 308 (aquatic […]