CLASS 3 – FAIL
, it is currently active and set for its next review cycle ending in February 2026 Updated ISO 8502-3 Dust Rating Chart The standard provides pictorial ratings for and descriptive classes for Quantity Rating Description of Dust Level Typical Action No particles visible under 10x magnification Very slight; particles visible under 10x but not naked eye Slight; particles just visible with normal vision Pass (Typical spec) Moderate; particles clearly visible (~0.5mm) Often Fail / Re-clean Heavy; particles between 0.5mm and 2.5mm Fail / Re-clean Very Heavy; particles larger than 2.5mm Fail / Re-clean Rösler Blog Key Procedure Steps