With this Test Guideline a standardized method is now available which determines the dispersion stability of nanomaterials in aqueous media in dependence of environmental conditions. The need for such a specific test guideline for the environmental risk assessment of nanomaterials is based on recommendations of OECD experts as dispersion stability influences mobility and availability of nanomaterials in the environment. So far no OECD Test Guideline for the determination of this property existed. Thus, data which now can be collected using this test guideline serve as substantial basis for further test strategies on environmental behavior and exposure of nanomaterials.
In addition to dissolution rate, dispersion stability in aqueous media features a fundamental parameter, which needs to be considered within an appropriate regulation of nanomaterials. For this reason, Germany demands to include this parameter as information requirement with the nanospecific adaptations of the European Chemical Regulation REACH.
The OECD Guidelines for the Testing of Chemicals comprise a set of standardized, international harmonized and accepted test methods and guidance documents used to characterize chemicals and to investigate their potentially harmful behavior and effect on human and the environment. These Test Guidelines were primary developed for soluble and organic chemicals. The behavior of nanomaterials clearly differs from that of chemicals. Thus, even though it is recognized that OECD Test Guidelines are in general applicable to nanomaterials, there is need for adaptation and addition.
The now adopted Test Guideline was developed by the Department of Environmental Geosciences at the University of Vienna on behalf of the German Environment Agency and with the financial support of the German Federal Ministry for the Environment, Nature Conversation, building and Nuclear Safety.
The development of the Test Guideline at the University of Vienna was summarized in a comprehensive scientific report. Upon finalisation, the report written in English language will be available at the UBA webpages on nanotechnology.