Faster ASEPTIC, Operating And Maintenance Manual

Page: 43 / 68

a D:GROUP Company
00254EN – Rev. 01 – 11/2012 43
13.G DEHS TEST FOR HEPA FILTERS
OBJECT AND PRINCIPLE OF THE TEST:
Check of the integrity of the HEPA filters through an analysis of the filtering system, able to find out possible
small leaks and/or defects altering the efficiency of the filters and at the same time to test leaks around
gaskets.
The HEPA filter system fitted to the isolator is tested for leakage by subjecting it to an aerosol on the
upstream side and measuring passage of the aerosol to the downstream side
INSTRUMENTS TO BE USED FOR TESTING:
1. Aerosol generator
2. Photometer
REAGENTS:
Liquid aerosol agent composed of Emery 3004 or equivalent in concentration of 60
µ
g/l.
Suitable measures must be taken to prevent or reduce the operator’s exposure to aerosol.
TEST PROCEDURE:
The photometer must be used at a threshold sensitivity specific to the test aerosol of 0.0001
µ
g/l and
capable of measuring aerosol concentrations up to about 80
µ
g/l.
The test must be performed as follows:
– Place the aerosol generator in such a way that the aerosol produced is immediately catched by the
barrier airflow and then recycled into the intake channel
– Switch the generator on and adjust the photometer to give a reading of 100% when sampling this
concentration
– Ensure that the threshold of reading sensitivity of the photometer is 0.0001
µ
g/l.
– Operate the isolator with airflow velocity as per specs.
– Using a sampling probe attached to the photometer scan the filters’ faces, seals and construction joints,
moving the sampling probe at not more than 30 mm/s
– Check the values read by the photometer constantly, in order to detect possible leakage.
– Acceptance criteria: downstream reading must be less or equal to 0.01%