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. This OECD TG on the dustiness determination of manufactured nanomaterials was developed to address the need for standardized dustiness test methods applicable to powders containing granular and fibrous Nano-Objects, and their Aggregates and Agglomerates.
Second commenting round on the Determination of Dustiness of Manufactured Nanomaterials
- Submission period
- 27 October - 8 December 2025
Background public consultation
Project description
The project was proposed to the OECD Test Guidelines Programme originally by Denmark and France in November 2018, and taken over by Denmark and Germany in 2021. This overall proposal is aiming at determining the dustiness of manufactured nanomaterials (MNs) and its subsequent use in the frameworks of worker exposure. The proposal intended to develop both a Test Guideline (TG) and an associated Guidance Document (GD), specifying how to apply the data generated with the TG. This is the second round of review and comments by the WNT; the first round took place in December 2024.
The first objective of the TG is to select the relevant methods to determine the dustiness of a powder (e.g. mass and number dustiness indexes). Nanomaterials representing different grades of dustiness have been tested in the validation exercise and the range of mass (mg/kg) and number based (#/m3) dustiness indices expected from the different methods were determined. Therefore, comparability of the different methods for their suitability for different nanomaterial types is now available. The proposed dustiness test methods utilize various dust generation devices, applying specified amounts of powders and energy inputs over designated time periods to quantitatively analyse dust characteristics. These methods simulate different powder processing and handling scenarios prone to dust generation, enabling a comprehensive assessment of the dustiness of powders containing granular and fibrous NOAA through metrics such as mass- and number-based dustiness indices, particle emission rates, and particle size distribution.
How to contribute
The draft Test Guideline is currently under a commenting round by the Working Party of the National Coordinators of the Test Guidelines Programmes 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 8 December 2025.
Document for public comments
