Compressed air filter integrity test


Would You know when the integrity test is required ? In my compressed air systems there are 0.2um filters before point in use. And now: we have one manufacturer’s device to making the integrity test of its filters. Another manufacturer can send to us his engineer for making the test. But third manufacturer needs to receive the filter, send it to another country to make the integrity test, then resend it to us. When I asked about possibility of destroying the membrane during transport they said the filter is packing carefully etc.

My question is: Do we need make the integrity test of new filter cardridge ? One manufacture says the test needs to be done because there is a little possibility of destroy the membrane during transport (in our HVAC systems we have the HEPA filters and we make the integrity tests after every exchange).

And how often it has to be making ? (we use the CA for drying the equipment, automation but of course the air has a contact with product in some machines).

Thanks in advance


Integrity test is a requirement as per GMP and Regulatory prespective. Every time you test for integrity and when it passes you are sure that the airfilter or any filter per say is performing up to its expectations by preventing bacteria down stream of filter and making the products protected from bacteria.
These tests are 2 types :

  1. Destructive testing
    2.Non destructive testing

Non destructive testing can be performed at your manufacturing facility by your validation Engineer.This is performed by wetting your membrane or cartridge with 70% IPA solution or 45% IPA solution or per say any solution given by manfacturer of that filter.
All you need to have is that wetting solution and solvent and also an integrity testing apparatus.
Normally these tests are done at a pressure of 30 to 40 Psi for Airfilters as they need some water miscible solvents like IPA( Iso Propyl Alcohol).

Durga Prasad.

You Can use any filter integrity tester like , IT4 , Palltronic Flow star, and manualy also , by using wetting agent like IPA.

There are many integrity tester manufacturers. The proper selection and usage is important and it should be compliant as per CFR and also should have electronic signatures.
Milliopre, Sartorius, Pall and Nunc are makin these automatic testers.

Frankly speaking all testers work on all membranes and cartidges.Once you change from manufacturer to manufacturer one should actually look into Operating condition of pressure and quantity of IPA used for wetting.
Mere IPA is not only important , the quality of water you mix IPA is also important. The most critical factor of test is how you dry back the membrane after this test.


  1. Analyse the area/process where you are using compressed air, if it is going to contact with product or its primary packaging material, you have to perform filter integrity before & after of operation.
  2. If compressed air is being used for drying pusposes only on controlled area then you have to do filter integrity on after every filter installation, then you can set a frequency for filter integrity. But make sure this equipment (dried by air) is not making direct contact with product & primary packaging material.