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Solid Particle Classes

Solid particles in compressed air can damage equipment, contaminate products, and affect processes. ISO 8573-1 defines 8 classes (0-7) based on the quantity and size of allowed particles.

Classification Table

ClassParticles per m³Concentration
0.1-0.5 µm0.5-1 µm
---------------------------
0Per user specification
1≤20,000≤400
2≤400,000≤6,000
3-≤90,000
4--
5--
6--
7--

Interpretation

  • Class 0: Special requirements defined by the user
  • Classes 1-2: Ultra-clean air, typical for electronics and pharmaceutical
  • Classes 3-4: Clean air for demanding applications
  • Classes 5-7: General quality air
Filtration

To achieve low particle classes, high-efficiency filters (0.01 µm) are required, properly installed and with regular maintenance.