The OECD expert meeting on ecotoxicology and environmental fate — Towards the development of improved OECD guidelines for the testing of nanomaterials

Abstract

On behalf of the OECD Working Party on Manufactured Nanomaterials (WPMN) an expert meeting on ecotoxicology and environmental fate of nanomaterials (NMs) took place in January 2013 in Berlin. At this meeting experts from science, industry and regulatory bodies discussed the applicability of OECD test guidelines (TGs) for chemicals to nanomaterials. The objective was to discuss the current state of the relevant science and provide recommendations to the OECD WPMN on (1) the need for updating current OECD TGs and the need for developing new ones specific to nanomaterials; and (2) guidance needed for the appropriate and valid testing of environmental fate and ecotoxicity endpoints for NMs. Experts at the workshop agreed that the majority of the OECD TG for chemicals were generally applicable for the testing of NM, with the exception of TG 105 (water solubility) and 106 (adsorption-desorption). Additionally, the workshop also highlighted considerations when conducting OECD chemical TG on nanomaterials (e.g., sample preparation, dispersion, analysis, dosimetry and characterisation). These considerations will lead to the future development of proposals for new TG and guidance documents (GDs) to ensure that OECD TG give meaningful, repeatable, and accurate results when used for nanomaterials. This report provides a short overview of topics discussed during the meeting and the main outcomes. A more detailed report of the workshop will become available through the OECD, however, due to the urgency of having OECD TG relevant for nanomaterials, this brief report is being shared with the scientific community through this communication.

Frameworks and tools for risk assessment of manufactured nanomaterials

“…Some of these protocols are based on the OECD Test Guideline (TG) 312: Leaching in Soil Columns, and involve soil column chromatography in disturbed soil to determine the leaching potential of the test substance, and the leaching potential of transformation products in soils under controlled laboratory conditions. These protocols involve detailed physicochemical characterization of the MNs and the exposure media by means of advanced analytical methods such as ICP-MS and Scanning Electron Microscopy (SEM) (Kühnel and Nickel, 2014). Other methods aim to measure extremely low number concentrations of MNs in complex environmental matrices by single particle ICP-MS (Tuoriniemi et al, 2014, Cornelis and.…”

Regulatory ecotoxicity testing of nanomaterials – proposed modifications of OECD test guidelines based on laboratory experience with silver and titanium dioxide nanoparticles

“…In 2013, an OECD ''WPMN Expert Meeting on Environmental Fate & Eco-Toxicology'' was held to further evolve the environmental testing of NMs. Several topics and test guidelines were comprehensively discussed (Kühnel & Nickel, 2014;OECD, 2014). Another workshop was organized in Washington in July 2014 focused on drafting an OECD guidance document on aquatic and sediment toxicology testing of nanomaterials.…”

Nanopharmaceuticals: Tiny challenges for the environmental risk assessment of pharmaceuticals

“…Furthermore, within the PBT assessment, the bioconcentration factor is determined in fish using the OECD 305 study based on the partitioning of the test substance between water phase and animal tissue. However, because nanomaterial uptake into organisms is not simply driven by passive diffusion, and equilibrium of the tested material in the test system can hardly be achieved, the use of this test to determine bioconcentration factors for nanomaterials is highly debatable [40,41]. An alternative guidance for testing the bioaccumulation of nanomaterials in fish via dietary uptake is under development.…”

“…However, adaptations are needed with an emphasis on sample preparation, dosimetry, test performance, and data interpretation to improve the harmony of the tests' performances and thus improve comparability of the test results [41]. Points to consider are the preparation of stock and working suspensions, the stability of test dispersions during ecotoxicological tests, and the metrics for reporting the test results [36].…”