2000 Volume 2 Issue 2 Pages 81-91
For both liquid and gas filters in aseptic processing, it has been stressed on the importance of integrity confirmation in site, before and after filtration. With newly developed water intrusion test (WI), only using water and gas, it is convenient to perform the test for hydrophobic air filters in site. In order to establish the WI procedure in site, here we pointed out on the followings: influential factors for WI results, test procedure, points to consider WI in site, and the case study with vacuum break filters of freeze dryer, especially installed in machine room. With regard to the influential factors for WI results, the changes in the temperature of test fluid and environment, test gas and water, and their introduction, filter cleanliness, filter types and size, air leakage in the upstream, test instrument and the stabilization time during the test etc. were described. According to WI, it is simple and different from the other kinds of test methods, especially on the wetting and drying procedure. Finally, from the test results using vacuum break filter installed in the machine room, it was convinced the importance of the temperature control between water and environment. In addition, in order to obtain high reproducible test results, and to do the effective trouble-shooting, it is important to be understood the influential factors and preliminary checking procedure, by the operators.
