New OECD Test Guideline for nanomaterials in the environment
The next step towards implementing the requirements for environmental risk assessment of nanomaterials: The new standard test method investigates the solubility and dissolution rate of nanomaterials under relevant environmental conditions. It therefore represents an important new building block for an appropriate environmental risk assessment within the framework of chemical safety regulations.
The OECD Test Guideline No. 322 enables the investigation of key parameters for assessing the behaviour and fate of nanomaterials in the environment. Using the newly developed methods, solubility and dissolution rates can be determined under relevant environmental conditions. On this basis, it is possible, on the one hand, to meet regulatory information requirements regarding the dissolution of nanomaterials. On the other hand, it is possible to determine whether nanomaterials released into the environment remain present as nanomaterials or are rapidly dissolved. This can provide a basis for deciding whether a nanomaterial-specific environmental assessment is necessary. Alongside other parameters such as dispersion stability or transformation, data on the dissolution rate are essential for assessing the environmental behaviour of nanomaterials. Information on the dissolution rate in biological and environmental media is therefore part of the requirements to be met for nanomaterials under the European chemicals regulation REACH.
The OECD test guidelines for the testing of chemicals comprise a series of standardised, internationally harmonised and accepted test methods and guidance documents, which can be used to characterise chemicals and investigate their potentially harmful behaviour and effects on humans and the environment. These test guidelines were developed primarily for water soluble, organic chemicals. However, the behaviour of nanomaterials in the environment and in humans differs significantly from that of these chemicals. While it is recognised that the existing OECD test guidelines are generally applicable to nanomaterials as well, there is nevertheless a need for adaptation and amendment.
The Test Guideline that has now been adopted was developed by the Department of Environmental Geosciences at the University of Vienna and the Fraunhofer Institute for Molecular Biology and Applied Ecology (IME) on behalf of the German Environment Agency and with funding from the Federal Environment Ministry. Under the leadership of these two research institutions, the Test Guideline was also validated in an international interlaboratory comparison test.