HEPA filter integrity failure in Fluid bed drier


During the retesting of HEPA filter integrity in fluid bed dryer, we have observed side leakages from the frames. However the filters were found to meet the acceptance criteria < 0.001%. He have also carried out non-particle count and were found to meet the acceptance criteria for ISO class 7. During investigation we had observed that the sealants used for sealing the gaps were aged and resulted in leakages. I need to investigate the impact ton the product quality. We had executed few of the validation batches before the incident. The microbial limits and the impurities are well within the limits. Can any one suggest the way forward?



I think that the acceptance criteria < 0.001% is not very suitable. Generally, acceptance criteria is < 0.01% for H13 and H14.