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Particle size distribution and number fraction of nanoform in SDS of EU

Posted Date:2025/1/7 1

3.1.1. Particle size distribution and number fraction of constituent particles

REACH Annex VI section 2.4.2 requires the reporting of the number based particle size distribution with indication of the number fraction of constituent particles in the size range 1 nm to 100 nm. When the Guidance refers to ‘particle size distribution’, it refers to the number based particle size distribution in line with the JRC Report [8]. When the Guidance refers to number fraction (of constituent particles or of nanoparticles), it refers to the number fraction of constituent particles in the size range 1 nm to 100 nm.

3.1.1.1. Distinguishing one nanoform from another

Each single nanoform has a specific particle size distribution where the variability in the distribution is within the batch-to-batch variability. Any variability in the particle size distribution beyond batch-to-batch variability creates another nanoform. The range of the values to be reported as described in the section 3.1.1.2.1 reflects the batch-to-batch variability.