Previously, we informed about the NANOMET workshop on the OECD Guidance Document (GD) 317 dealing with the aquatic and sediment toxicity testing of nanomaterials. By the end of last week another NANOMET online seminar took place. There, the scope, content and practical use of the testing guideline (TG) 318 was discussed. It particularly focused on determining the dissolution rate but also the dispersion stability for toxicity testing, accompanied in the Guidance Document 318.

At present – and in contrast to the previous presentation of GD 317 – unfortunately no public available recording of the online seminar exists. Update: In the meanwhile the respective recording was uploaded and is now available for the public on YouTube. We embedded the YouTube-video below.

However, as we already informed about the OECD 318 guideline in one of our previous posts – also linking to our respective video presentation (above) – we today want to inform you about the scope and the content of the 53 pages heavy accompanying GD 318.

Scope of OECD GD 318

The dissolution rate but also the dispersion stability of nanomaterials in the environment are very important parameters. These, ultimately affect their fate and hence have a direct impact on their environmental risk assessment. As dissolution rate and dispersion stability, frequently depend on each other, an overarching guidance document was needed to connect these factors. This is now being represented by the OECD GD 318.

The document addresses methods to assess the dissolution rate and dispersion stability for nanomaterials in environmental aqueous media. It is relevant for nano solids but also their aggregates and agglomerates. In more detail, the GD provides indication for the influence of different experimental conditions, on the performance and results of the used methods. Furthermore, the document discusses modifications and /or supplements to these methods.

Content of OECD GD 318 [referring to respective chapters]

1. Flowthrough and bench test methods to determine solubility and dissolution rate [chapter 2]

2. Specific guidance on TG 318 [chapter 3]:
  • Additional experimental conditions
  • Support to account for heteroagglomeration
  • Deriving attachment coefficients
  • Guidance for the interpretation and presentation of data with regards to the end point

3. The use of the gained data for further fate and effect testing / assessment strategies & influence of two endpoints on each other, for example dispersion stability on dissolution rate and the other way around is discussed [chapter 4]

4. Recommendations for the use of output data to derive input data / parameters for exposure modeling [chapter 5]

5. How to use the GD with regards to the other [upcoming] OECD TGs and GDs [chapter 6]
  • Aquatic and sediment toxicity testing
  • Accumulation potential of nanomaterials in fish
  • Fate estimations in soil and sediment: Advice on screening possibilities for dispersion stability and dissolution rates under varying environmental conditions

Here is a link to the document on the OECD webpage.
Contact us in case you have questions, need advice or if you want us to conduct the study for you.
We are experienced and have the respective equipment ready to be used.

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picture by Republica on Pixabay