The German Umweltbundesamt  (Environment Protection Agency), has released a document entitled Clarification of methodical questions regarding the investigation of nanomaterials in the environment.  This results presented in this publication were included in the OECD Test Guideline on Dispersion stability of Nanomaterials in Simulated Environmental Media, which was approved in April 2017 and published in October 2017.

The study identified the following parameters as influential on the agglomeration behavior of particles : ionic strength, pH, concentration of Dissolved Organic Matter (DOM), particle (number) concentration, particle nature and surface chemistry,  particle size, particle density and presence/absence of CO2 in the atmosphere.

Umweltbundesamt reports that silver nanoparticles (NM300K), titanium dioxide nanoparticles (NM105) and carbon nanotubes (NM400) were used for a proof-of-principle.

The report also features a decision tree to determine if a material of interest requires only screeening or in-depth testing.

Please follow this link for the Umweltbundesamt report Clarification of methodical questions regarding the investigation of nanomaterials in the environment(link is external) and this link for the  OECD Test Guideline on Dispersion stability of Nanomaterials in Simulated Environmental Media.