Integrity Testing

Integrity testing is a certification that controls the quality of filter element production. In the biopharmaceutical industry, integrity testing ensures the safety of the sterilization process by confirming the integrity of the filter itself, the tightness of the filtration system, the correct installation of the process, and that the filter is undamaged and meets manufacturing specifications.

STEMart provides comprehensive and reliable integrity testing services to make sure the installed filter meets the standards provided by the manufacturer, and ensure the tightness of the filtration system.

Test Samples

Needle filter, capsule filter, plate filter, cartridge filter, ultrafiltration membrane bag, ultrafiltration column, and various irregular filters

Standard Tests

• Destructive Testing
  • Bacterial challenge experiment: targeting filters with bacterial retention capabilities
  • Particle challenge experiment: targeting partial prefilters with particle retention capabilities
• Non-Destructive Testing
  • Bubble point test: When the liquid completely wets the filter membrane, the liquid will remain in the membrane pores due to surface tension and capillary force, and the bubble point value is the minimum pressure to squeeze the liquid out of the largest membrane pore.
  • Diffusion test: At differential gas pressures below the bubble point, gas molecules migrate through the water-filled pores of a wetted membrane following Fick's Law of Diffusion. The gas diffusion flow rate of the filter is proportional to the differential pressure and the total surface area of the filter. The gas diffusion through the membrane is measured at a pressure of approximately 80% of the minimum bubble point to determine the integrity of the filter.
  • Pressure hold test: The pressure hold test, also known as pressure decay or pressure drop test, is a variation of the diffusion test. In this test, a highly accurate gauge is used to monitor upstream pressure changes due to gas diffusion through the filter. Since there is no need to measure gas flow downstream of the filter, any risk to downstream sterility is eliminated.
  • Water intrusion test: The water intrusion method is specifically designed for testing hydrophobic filter elements. Hydrophobic membranes resist water, and the smaller the pore size, the greater the pressure required to squeeze water into the hydrophobic membrane. Therefore, under a certain pressure, the water flow squeezed into the filter membrane can be measured to determine the pore size of the filter element.

For more information about our integrity testing services, please contact us.