PRECAUTIONS:
Before starting this test, ensure that required room air changes are
adjusted and verified.
Carry out this test only after verification of operational air
velocities.
Use mask and hand gloves during performing the test.
PROCEDURE:
- Start the respective LAF or AHU or other equipment for which HEPA filter integrity test to be performed. Operate the equipment as per respective SOP.
- Ensure that, all the doors of the respective areas are properly closed.
- Align the smoke generator in such a way that the DOP aerosol will be introduced properly in to the air stream ahead of the HEPA filter.
- Open the required numbers of nozzles of the aerosol generator until the DOP challenge concentration reaches 100 mg/lt.
- Clean the photometer and its probes with a clean room wiper duly absorbed with a germicidal solution before taking the instrument in the clean area.
- Read the upstream challenge concentration with the photometer and ensure that the digital scale is set for 100 % concentration.
- Leave the upstream challenge pipe probe on the photometer upstream nozzle itself so that the challenge concentration can be checked during the scanning cycle.
- Scan each filter in the room by holding the photometer probe approximately 2” away from the filter face and moving the probe with overlapping strokes.
- The traverse rate should not be more than 10 ft/min. so that the entire filter face and the fitment periphery of the filter can be checked totally. Ensure that the probe travels specifically through the grey areas like the bond between filter frame and medium, installation joints etc. so that the aerosol does not bypass the filter medium.
ACCEPTANCE CRITERIA:
Acceptable aerosol droplet size distribution by light scattering
means,
i) Less than 3.0 micron particulate
--- > 99 %
ii) Less than 2.0 micron particulate ---
> 97 %
iii) Less than 1.5 micron particulate ---
> 95 %
iv) Less than 1.0 micron particulate --- > 92 %
v) Less than 0.72 micron particulate
--- > 50 %
vi) Less than 0.45 micron particulate ---
> 25 %
vii) Less than 0.35 micron particulate ---
> 11 %
Percent penetration of DOP should be less than 0.01%.
If any leakage is found, then seal it with silicon sealant certified
for use in clean room. The maximum single silicon sealed joint should not be
more than 2 inch in length and ½” in width. The sealed
area of filter should not be more than 5% of the filter area.
FREQUENCY: Yearly.
