The OECD has released Test Guideline (TG) 322, introducing a harmonised approach for determining the solubility and dissolution rate of nanomaterials in support of environmental fate and risk assessment.
The guideline sets out standardised methods for measuring how nanomaterials dissolve under environmentally relevant pH conditions. It includes two test approaches: a 24-hour batch test to determine apparent solubility, and a time-resolved batch test that measures both apparent solubility and dissolution rate over an extended period.
The extended test is conducted at pH 5, 7 and 8, with pH 7 serving as the default reference condition to support comparability across studies and materials.
