Compressed Air System Qualification Requirements

Compressed Air System Qualification Requirements

Compressed air system consists of 4 components:

  • Air Compressor: Which compress atmospheric air to higher pressure
  • Air Dryer: Remove water from compressed air
  • Air Filters: Remove any further containments in compressed air
  • Air Tank: Acts as reservoir for compressed air


There are two types of air compressor:


There are two types of Air Dryers:


Types of Air filters:


The typical Compressed Air system consists of an oil-free air compressor that compresses the ambient air and an air dryer connected to an air receiver surge tank that supplies air throughout the distribution system. Where a non-oil-free air compressor is used, the Compressed Air passes through a coalescing filter and oil vapor absorber filter where the hydrocarbons are removed and then passes into the surge tank and distribution system.

The following table matches the ISO 14644 clean room classification and its equivalent classes in ISO 8573 Purity Classification:


Qualification requirements of compressed air:

  1. All use points including the compressed air exit point from the air compressor will be sampled.
  2. Testing will be in accordance with documented procedures.
  3. Environmental tests (microbiological and nonviable particulate) will be taken for information only for non-sterile use.
  4. Environmental tests for sterile use must meet the criteria for the area of use.
  5. Suggested acceptance criteria for the Compressed Air distribution system at product point of use (using a 0.22 micron in-line filter in controlled areas) include the following based on ISO 8573:


A. Pressure Dew Point


B. Oil Content


C. Particle Count