Table 1 Overview of the possibilities for further improvements of the ECHA guidance identified in the current appendices and the changes that we suggest
ECHA TG | Section in ECHA TG | Page | Room for improvement in the current text | Section in this paper addressing this issue | EnvNano recommendation(s) related to this issue |
|---|---|---|---|---|---|
Nanospecific Appendix R.7a v2 | 1.1 General advice on how to perform nanomaterials ecotoxicity and fate testing | 6 | No mentioning of the importance of understanding and considering the pros and cons of various characterization methods in the listed prerequisites | – Appropriate nanomaterial dispersion is key for reliable ecotoxicity testing – Quantifying nanomaterial dissolution is crucial for disclosing ecotoxic effects – Nanomaterial surface reactivity is important as toxicity indicator | EnvNano recommendation # 1 on dispersion EnvNano recommendation # 2 on dissolution EnvNano recommendations # 3 on ROS |
Nanospecific Appendix R.7a v2 | 1.1 General advice on how to perform nanomaterial ecotoxicity and fate testing | 7 | No mentioning of the importance of preparation of the stock solution to minimize agglomeration/aggregation | – Nanomaterial dispersion is key for reliable ecotoxicity testing | EnvNano recommendation # 1 on dispersion |
Nanospecific Appendix R.7b v2 | 1.2.1 Aquatic pelagic toxicity | 8 | Could be more specific with regard to how to determine whether an NP dissolves fast or not | – Quantifying nanomaterial dissolution is crucial for disclosing ecotoxic effects | EnvNano recommendation # 2 on dissolution |
Nanospecific Appendix R.7b v2 | 1.2.1.1 Test guidelines specificities for aquatic toxicity | 9 | Not sufficiently specific regarding OECD TG 201 on algal growth inhibition testing | – A shortened exposure may reduce nanomaterial transformations in ecotoxicity tests and elucidate nanomaterial-specific effects and exposure dynamics – Using freshly prepared nanomaterial-suspensions may underestimate toxicity – It is important to distinguish between physical and chemical effects in aquatic toxicity tests | EnvNano recommendation # 4 for acute algal tests with nanomaterials EnvNano recommendation # 5 on not only using a freshly nanomaterial-suspensions EnvNano recommendation # 6 on shading and physical effects |
Nanospecific Appendix R.7b v2 | 1.2.1.1 Test guidelines specificities for aquatic toxicity | 9 | Not sufficiently specific regarding OECD TG 202 on daphnia magna acute toxicity testing | – Uptake and depuration depend on nanomaterial functionalization – It is important to distinguish between physical and chemical effects in aquatic toxicity tests | EnvNano recommendation # 8 for acute daphnia tests with nanomaterials EnvNano recommendations # 6 on shading and physical effects |
Nanospecific Appendix R.7b v2 | 1.2.1.1 Test guidelines specificities for aquatic toxicity | 9 | Could be more specific regarding OECD TG 211 on daphnia magna chronic toxicity testing | – Toxicity and uptake is feeding dependent | EnvNano recommendation # 7 for long-term daphnia tests with nanomaterials |
Nanospecific Appendix R.7c v2 | 2.1.1. Aquatic bioaccumulation | 7 | No consideration of integration of the nanomaterials into food sources and potential trophic transfer | – Trophic transfer is an important uptake pathway for nanomaterials | EnvNano recommendation # 9 for bioaccumulation tests with nanomaterials |
R.7b Endpoint specific guidance | 7.8.2 Information requirements for aquatic pelagic toxicity | 15 | Limited nanospecific relevance of existing general information requirements | – Appropriate nanomaterial dispersion is key for reliable ecotoxicity testing – Quantifying nanomaterial dissolution is crucial for disclosing ecotoxic effects – Nanomaterial surface reactivity is important as toxicity indicator | EnvNano recommendation # 1 on dispersion EnvNano recommendation # 2 on dissolution EnvNano recommendation # 3 on ROS |
7.8.4.1 Evaluation of available information on aquatic pelagic toxicity | 22–23 | Klimisch scoring does not take nanospecific properties into account | – Data selection for dose–response assessment derivation should be structured, reproducible and transparent and support use on non-guideline data | EnvNano recommendation # 10 on evaluation of data |