The OECD Working Party on Manufactured Nanomaterials (WPMN) and the OECD Working Party of National Coordinators of the Test Guidelines Programme (WNT) have been working collaboratively to address the specific challenges of nanomaterials safety testing. Over recent years, they have developed and continue to refine OECD Test Guidelines (TGs) and Guidance Documents (GDs) to produce reliable safety data for nanomaterials. The dedicated OECD webpage provides more background information.
Second commenting round on the draft Test Guideline on Determination of the Solubility and Dissolution Rate of Nanomaterials for Environmental Fate Assessment
- Submission period
- 11 Dec 2025 - 29 Jan 2026
Background public consultation
Project description
The scope of this TG is to provide cost-efficient and easy to implement methodologies to determine nanomaterials solubility and dissolution rate in water at different environmentally relevant pH values with a passive pH control (buffers) for environmental fate assessment. This TG consists of two parts: part A is a batch test that delivers the apparent solubility of a nanomaterial after 24h at pH 7 (as default; in addition, pH values between 5 and 8 can be applied). Part B is a time-resolved batch test that delivers the apparent solubility of a nanomaterial after 72h at pH 5, 7 and 8, and the dissolution rate as long as depletion of the nanomaterial or saturation of the solution is not reached before 4h. It must be noted that due to the given starting concentrations of the tests (Part A 100 mg/L, Part B 10 mg/l) the highest solubilities that can be correctly determined are 100 mg/L (Part A) and 10 mg/L (Part B).
How to contribute
The draft Test Guideline is currently under a second commenting round by the Working Party of the National Coordinators of the Test Guidelines Programmes (WNT) and open for comments from the public at the same time. Interested parties are invited to contact their National Coordinators at least a week before 29 January 2026.
