SOP for Leak Test of HEPA Filters

Learn How to Write SOP for leak test of HEPA filters in Pharmaceutical plants.

1.0 PURPOSE

To give instructions on how to make sure HEPA filters are functional and intact.

2.0 SCOPE

This SOP is applicable to all HEPA filters installed in clean rooms for Pharmaceutical Plant

3.0 ASSOCIATED DOCUMENTS

 Nil

Read Also: SOP for Guidelines for Maintenance Procedure

4.0 RESPONSIBILITIES

5.1Engineering Officer/ Sr. officer is responsible for ensuring that the filters are intact & suitable for operation.

5.2 The head of the Engineering/Technical Department is responsible for approving the procedure.

5.0 ACCOUNTABILITY

Head of department

6.0 PRECAUTION

6.1 Allow only trained staff to carry out this system.

6.2 Use hand gloves, mask & safety goggles during chemical handling. 

Read Also: SOP for Planned Preventive Maintenance Schedule (PPM)

7.0 PROCEDURE:

7.1 Scan the entire filter face including the perimeter with the probe of the photometer in overlapping Strokes, traversing at approximately 10 feet per minute. (FPM).

7.2 Observe the percentage of leakage directly on the photometer.

7.3 Filter repair patches should not take up more than 5% of the total filter face surface and should not be wider than 1.5 inches in length. Total number of patches Should not be more than 1.5 inches. Total number of patches should not exceed 5 numbers/ filter.

7.4 Record the manometer reading.

7.5 Ensure the power supply of the DOP photometer.

7.6 Start the compressed air/Nitrogen gas to generate the test aerosol at a minimum of 20 psi.

7.7 Direct the test aerosol at the return air point or fresh air intake of the LAF.

7.8 Wait until the photometer displays ‘0’ (ZERO).

7.9 Measure the downstream concentration by holding the probe approximately 1 inch away from the face of the filter.

7.10 Scan the entire filter face including the perimeter with the probe of the photometer in overlapping Strokes, traversing at approximately 10 feet per minute. (FPM).

7.11 Observe the percentage of leakage directly on the photometer.

7.12 Filter repair patches should not take up more than 5% of the total filter face surface and should not be wider than 1.5 inches in length. The total number of patches should not be more than 1.5 inches. Total number of patches should not exceed 5 numbers/ filter.

7.13 If the above-mentioned limit exceeds, then replace the filters and check the integrity of the filter.

7.14 Check the air velocity of individual Hepa filters by keeping the anemometer probe approximately 6” away from the filter.

7.15 Note down the reading and if the average reading is not within the acceptable limit replace the filter.

7.16 Limits for the average velocity 90 fpm +/-20%,0.45M/S+/-20%

7.16.1 Ahu/Plenum Mounted HEPA Filters

7.16.1.1 Start the AHU

7.16.1.2 Start the compressed air/nitrogen gas to the DOP generator to generate the test aerosol, at a minimum of 20 psi, and monitor the pressure.

7.16.1.3 Direct the test aerosol at the return air pump or Fresh air intake of AHU.

7.16.1.4 Ensure the power supply of the DOP photometer.

7.16.1.5 Put the photometer selector switch on upstream mode.

7.16.1.6 Check the upstream conc. Of DOP before HEPA at AHU/plenum. Wait until the photometer displays 100% upstream conc.

7.16.1.7 Remove the tube of the photometer seal the AHU  port and ensure Zero leakage through the port.

7.16.1.8 Put the photometer selector switch on Downstream mode.

7.16.1.9 Wait until the photometer displays Zero.

7.16.1.10 Open the AHU/PLENUM door and enter inside.

7.16.1.11 Measure the downstream conc. By holding the probe approximately 1’’ away from the filter face.

7.16.1.12 Scan the entire filter face including perimeters with the probe of the photometer in overlapping strokes, traversing at approximately 10 feet per minute.

7.16.1.13 Scan the entire filter face including perimeters with the probe of the photometer in overlapping strokes, traversing at approximately 10 feet per minute.

7.16.1.14 Observe the percentage of leakage directly on the photometer.

7.16.1. 15 If any leakage is observed through sealing of the filter tighten the filter nuts and check again for any leakage.

7.16.1.16 If the air leakage is more than 0.01% of the upstream aerosol conc. Then repair it.

7.16.1.17 Repair patches on filters should not exceed a maximum of 5% of the total filter face area. and the maximum width or height of each patch should not be more than 1.5 inches. Five numbers or filters should be the maximum number of patches overall.

7.16.1.18 Inform quality assurance and concerned departments.

7.16.1.19 A report of filter integrity checking should be obtained from a third party.

7.16.1.20 DOP leakage up to 0.01% of the stream challenge aerosol conc.

8.0 ABBREVIATIONS

8.1 HEPA  –  Hign Efficiency Particulate Air

8.2 FPM: Feet Per Minute

8.3 DOP: Di-Octyl Pthalate

8.4 LAF: Laminar Air Flow

8.5 AHU: Air Handling Unit

8.6 IES: Institute of Environmental Science

8.7 M/s: Meter per second

8.8 Psi: Pounds per square inch

8.9 SOP: Standard Operating Procedure

9.0 ANNEXURES

Nil