Event Dates: 
Wednesday, September 20, 2023 - 14:00 to 15:30
Event Venue: 
Online event

You are invited to join the webinar on Test Guideline No. 126: Determination of the Hydrophobicity Index of Nanomaterials Through an Affinity Measurement that will be held on Wednesday 20 September at 14:00-15:30 CEST / 08:00 - 09:30 EDT. The event is free of charge and simultaneous interpretation will be provided in English and Spanish.


This webinar will present the method to determine the hydrophobicity index (Hy) of nanomaterials (NMs), through an affinity measurement, described in the OECD Test Guideline No. 126. In this Test Guideline, Hydrophobicity is defined as "the association of non-polar groups or molecules in an aqueous environment which arises from the tendency of water to exclude non-polar molecules". By measuring their binding rate to different engineered surfaces (collectors), Hy expresses the tendency of the NMs to favour the binding to a non-polar (hydrophobic) surface because of its low affinity for water. The method applies to NMs dispersed in an aqueous solution or to NM powders after their dispersions in aqueous solutions, with or without a surfactant, using a recommended protocol. Through this webinar, you will be able to learn the use and limitations of this Test Guideline, as well as on the validation exercise that was done to support its development.