Compressed Air

Air Compressor Package for

Pharmaceutical & Biotech Industries

Chapter No.: 1.0

Revision No. : 00

Specification Date : 02.12.2010

Compressed Air:Introduction:Compressed air is one of the important utility considered in pharma & biotech industries; it is required in many applications, for example, as breathing air, for operating equipment and instruments, for process, etc. Knowing the proper air quality level required when considering FDA enforced cGMP is important in selecting the air compressor package unit.

In most cases the compressed air used shall be at least as clean as the air in the room where it is being used. In semiconductor work this may be very clean, such as class 2, 1 or even 0. In the semiconductor industry even the smallest particle on the surface of a piece of ultra pure silicon can potentially destroy the resultant IC or Processor. But, in the case of pharmaceutical manufacturing the situation is quite different, the quality is dependent basically on the purpose it is intended to be used for eg: flushing of the utilities from the reactor jacket, transferring of the process media, for pneumatically operated instruments & equipments, for breathing purposes in emergencies, etc.,

Standards:Many international standards have been in practice in determining the quality of the compressed air, like the British Compressed Air Society, International Standards Organization (ISO), the Compressed Air & Gas Institute (CAGI), etc. The most widely accepted standards is the ISO 8573 relating to the quality of compressed air.

The ISO 8573 standard is made up of nine parts, part 1 specifying the quality requirements of compressed air and part 2 to 9 specifying the methods of testing for a range of contaminants. In 2001, the ISO 8573.1 air quality standard was amended in an effort to provide more stringent air quality specifications for critical applications and the latest revision is expressed as ISO 8573.1: 2001. Within ISO8573.1 : 2001, a number of quality classes are shown in tabular form, each specifying the maximum amount of solid particulate, water and oil allowable per cubic meter of compressed air.

ISO 8573-1.2001

Solid ParticleWater

OilMaximum number of particles per m3 Total Oil

0.1 - 0.5 0.5 - 1 1.0 - 5 Particle

size Concentration

Pressure Dew Point Liquid

(Aerosol liquid & Vapor)

Class micron micron micron micron mg/m3 °C g/m3 mg/m3 0 As specified by the equipment user or supplier 1 100 1 0 - - -70 - 0.012 100,000 1,000 10 - - -40 - 0.13 - 10,000 500 - - -20 - 14 - - 1,000 - - 3 - 55 - - 20,000 - - 7 - -6 - - - 5 5 10 - -7 - - - 40 10 - 0.5 -8 - - - - - - 5 -9 - - - - - - 10 -

Specifying air purity in accordance with ISO 8573-1 : 2001 When specifying the purity of air required, the standard must always be referenced, followed by the purity class selected for each contaminant (a different purity class can be selected for each contaminant if required). An example of how to write an air quality specification is shown below:

ISO 8573-1: 2001 Class 1.2.1

File Name :Air Compressor Checked By :

Prepared By : DAV Approved By :Page 1 of 4



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ISO 8573-1: 2001 refers to the standard document and its revision, the three digits refer to the purity classifications selected for solid particulate, water and total oil. Selecting an air purity class of 1.2.1 would specify the following air quality when operating at the standard’s reference conditions:

Class 1 ParticulateIn each cubic meter of compressed air, no more than 100 particles in the 0.1 - 0.5 micron size range are allowed, in each cubic meter of compressed air, no more than 1 particle in the 0.5 - 1 micron size range is allowed, in each cubic meter of compressed air, no particles in the 1 - 5 micron size range are allowed.

Class 2 WaterA pressure dew point of -40°C or better is required and no liquid water is allowed.

Class 1 OilIn each cubic meter of compressed air, not more than 0.01mg of oil is allowed. This is a combined level for both oil aerosol and oil vapor.

ISO 8573-1: 2001 Class 0 HighlightsThe ISO 8573-1: 2001 table includes a class 0 for each type of contaminant. Any applications requiring compressed air purity which is higher than the levels shown in class 1, then class 0 allows the user and the equipment manufacturer & supplier to agree their own levels within the following guidelines:

The purity levels selected must be more stringent than those of class 1 The purity levels selected are measurable with the test equipment and the methods of ISO 8573 parts

2 to 9 The agreed levels are written as part of the air quality specification

Important Note: Class 0 does not mean zero contamination allowed in the compressed air. Manufacturers should not state products comply with class 0 unless purity levels have defined and

agreed with the user Purity levels beyond the accurate measurement capabilities given in ISO 8573 parts 2 to 9 should not

be selected as there is no accurate product performance. To operate a cost effective compressed air system, class 0 should only be specified at the point of use

and for the most critical of application.

Contaminants:

ISO 8573 series as it is this document which specifies the amount of contamination allowed in each cubic meter of compressed air lists the main contaminants as Solid Particulate, Water & Oil. The three major impurities influence each other (e.g. solid particulate agglomerates in presence of oil or water to form larger particles, oil & water form an emulsion) and sometimes are deposited or condensed (e.g. oil vapor or water vapor) inside the pipe work of a compressed air system. Other contaminants are also considered, including microbiological organisms and gaseous contaminants.

Solid particle: Solid particle properties are important and are characterized by density, shape and by hardness. Concentration of particles shall be in accordance with ISO 8573-4. Water: Atmospheric air always contains water vapor. Air when compressed the partial pressure of the water vapor increases but owing to the increase in temperature caused by the compression, no water precipitates. When the air is subsequently cooled water will condense to liquid, but the air will be fully saturated with water vapor.





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Oil: Oil in compressed air can belong to one or more of three categories: Liquid, aerosols or vapor. When considering oil vapor content of compressed air it is important to refer the temperature as this affects the ratio of vapor to total oil content. Testing for vapor should be carried out in conjunction with the test for aerosols & bulk liquid so the various phase concentrations may be discerned.

Miscellaneous contaminants:Gaseous: Atmospheric air not only contains common contaminants generally identified for treatment but also gaseous contaminants which may be present in varying amounts depending on location. Microbiological organisms: Are generally considered to be solid contaminants introduced by a number of means. If a microbiological organism is considered as a solid particle then the measurement method identified in ISO 8573-4 is used. If the colony forming activity of bacteria, fungi or yeasts important then this can be identified using a recognized standard.

StandardsMeasurement of the above water & oil contaminants shall be in accordance with ISO 8573-2, 3 & 5 as explained below.

- Part 2: Measuring oil aerosols and oil liquid content of compressed air,- Part 3: Measuring Humidity- Part 4: Measuring solid particles- Part 5: Measuring Oil vapor and organic solvent content

Further parts of ISO 8573 are under preparation for measuring gaseous contaminant content - Part 6: Measuring gaseous contaminant content- Part 7: Determining viable microbiological contaminant content- Part 8: Measuring solid particles – contaminants & purity classes (by mass concentration of

solid particles)- Part 9: Measuring liquid water content

To note, in absence of the above under preparation standards, other recognized standards shall be used for the measurement following the below rules:

- Measurement shall be based on a number of samples taken during a suitable length of time.- Measurement should be carried out at the actual operating pressure & temperature.- The purity classes of a compressed air system should be based on the mean value of an

agreed number of measurements (carried out at the actual operating conditions as otherwise the balance between impurities in liquid, aerosol or gaseous form will be altered).

- The purity classes are relevant only at the point of measurement.

The content of particles, water and oil in compressed air varies due to sudden changes in the intake air, to the wear of components as well as to changes in flow, pressure, temperature and ambient conditions.

Compressed Air Packaged Unit:Classification:

1. CompressorBased on Compressor Type: Reciprocating, Screw, Centrifugal …Based on Cooling Type: Air cooled, Water cooled Based on Lubrication: Lubricated - Oil, Water lubricated (oil free)

Non-lubricated 2. DrierBased on type of drier: Refrigerated, Adsorbent type

3. Filter





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Specific type of filter shall be based on the class and purity of compressed air required depending on the application, classified as nominal & absolute filters. Classification of filters based on the applicability:High Efficiency Water SeparatorsDepth Filtration – Coalescing & Dry Particulate FiltersMembrane Filtration – Air membrane & Liquid membrane

4. ReceiverReceiver is based on the capacity and the operating pressures.

5. Air Pressure RegulatorsThese are dependent on the compressed air operating pressure (generation) and on the pressure requirement at the user point.



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Compressed Air