Fraunhofer Institute for Molecular Biology and Applied Ecology IMEGermany* is leading the new OECD project 3.22 of the Test Guideline Programme to develop a testing protocol adapting OECD TG 321 for testing the bioaccumulation potential of engineered nanomaterials using the freshwater amphipod Hyalella azteca. The method development and refinement have been done by the Fraunhofer Institute for Molecular Biology and Applied Ecology IME with financial support of the German Environment Agency (Umweltbundesamt – UBA) and the German Federal Ministry of Research, Technology and Space (BMFTR).
To achieve a high degree of maturity of the method before submitting the draft document describing the testing procedure for commenting at OECD level, we plan to perform an international comparison study, scheduled for summer/fall 2026 – spring 2027.
In preparation of the comparison study we plan to hold an online meeting with interested experts to discuss possible questions regarding the study or the protocol at the 17th of June, 2026.
The test is based on
- the exposure of the benthic amphipod via the aqueous media (bioconcentration tests)
- the exposure of the benthic amphipod via experimental diet (biomagnification tests)
All necessary methods—including recommendations for analytical techniques—are described in detail in the protocol, which will be shared with all laboratories interested in participating in the interlaboratory study.
We are looking for interested partner laboratories to participate in the online meeting and comparison study (conducting one or more test) to allow the evaluation of the feasibility and robustness of the proposed method(s) given in the intended document.
Participation in the online meeting is not mandatory for joining the comparison study. The coordinators will be available throughout the project to support participants and address any questions regarding the protocol and related aspects.
As part of the comparative study, four nanomaterials will be evaluated in both bioconcentration and biomagnification tests; these materials and respective characterization data will be supplied by the coordinators:
Gold nanoparticles (nAu); Copper(II) oxide nanoparticles (nCuO); Cerium(IV) oxide (nCeO2) and 14C-labelled Polystyrene nanoparticles (14C-nPS)
- Laboratories may also participate even if they are able to conduct only one of the tests!
- Test materials will be centrally distributed to participating laboratories by the coordinators free of charge.
- In-house elemental analysis is required for testing nCeO₂ in the bioconcentration assay!
- Testing of ¹⁴C-nPS requires documented proof of an official or regulatory license to handle radioactive substances!
The allocation of studies—i.e., which participants test which materials in which assays—will be determined in consultation with the interested parties and coordinated by the coordinators.
*Project financed by the German Federal Ministry of Research, Technology and Space (BMFTR), grant agreement number FKZ 03LW0729.