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Air Quality: ISO 8573-1

ISO 8573-1 is the international standard for specifying compressed air quality.

The Three Contaminant Categories

ISO 8573-1 classifies air purity into three independent categories:

  1. Solid particles (ISO 8573-1)
  2. Water (ISO 8573-1)
  3. Total oil (ISO 8573-1)

Each category has its own numerical classification, where lower numbers = cleaner air.

How to Specify Air Quality

The specification is written as three numbers separated by periods:

ISO 8573-1:2010 Class [Particles].[Humidity].[Oil]

Examples:

SpecificationMeaning
1.4.1Very clean: particles class 1, PDP +37°F, oil 0.01 mg/m³
2.4.2Clean: particles class 2, PDP +37°F, oil 0.1 mg/m³
4.6.4Basic: particles class 4, PDP +50°F, oil 5 mg/m³