Level Chart Pdf Updated: Iso 85023 Dust

| Coating Environment | Acceptable Dust Quantity | Max Particle Size | Recommended Action | | :--- | :--- | :--- | :--- | | | Class 1 or 2 | <100 µm | High-pressure fresh water rinse before coating. | | Chemical Storage Tank Lining | Class 1 | <50 µm | Vacuum cleaning + tack rag immediately before coating. | | Bridge Structural Steel (Atmospheric) | Class 3 | <200 µm | Compressed air blow-down acceptable. | | Pipes buried in soil | Class 3 | <300 µm | Minor dust acceptable if primer is high-build. | | Recreational equipment / handrails | Class 4 | <400 µm | Cosmetic only – structural risk low. |

ISO 8502-3 is the international standard used to assess the quantity and size of dust particles on steel surfaces prepared for painting. Ensuring a surface is "dust-free" is critical because even invisible particles can cause coating failure, blistering, or poor adhesion. iso 85023 dust level chart pdf updated