SOP Title: Procedure for Validation of Laminar Air Flow
- Objective:
To lay down the procedure for Validation of Laminar Air Flow / Reverse Laminar Air Flow.
- Scope
This procedure is applicable for Validation of LAF in the Microbiology, Sampling Booth RLAF and Dispensing Booth RLAF.
- Responsibility:
3.1 Quality Control Department: To prepare and review the SOP. To follow the procedures for Validation of LAF as per this SOP.
- Quality Assurance Department: To review and approve the SOP and Annexure.
- Accountability:
Head Quality Control Department, Head Quality Assurance Department.
Procedure:
| 5.1 | Safety Precautions/Instructions: | ||||
| 5.1.1 | Ensure that Laminar Air Flow Unit is properly installed in a clean environment. | ||||
| 5.1.2 | Ensure that pre filters of Laminar Air Flow Unit are clean. | ||||
| 5.1.3 | Before Starting the activity ensure that LAF is properly Cleaned. | ||||
| 5.2 | Procedure for Validation: | ||||
| 5.2.1 | Validation of LAF is carried out by performing following tests.
1. HEPA Filter Integrity by PAO Test. 2. Air flow Velocity: Unidirectional Airflow. 3. Non-Viable Particle Count Test. |
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| 5.2.2 | Validation study of LAF is applicable to LAF in Microbiology, Sampling Booth RLAF and Dispensing Booth RLAF. | ||||
| 5.3 | 1. HEPA Filter Integrity by PAO Test: | ||||
| 5.3.1 | LAF consists of two filters and are named as F1(Left side) and F2(Right side). | ||||
| 5.3.1 | Arrange single phase power supply as well as air connection with 20psi (1.5kg) pressure. | ||||
| 5.3.2 | Switch ON Aerosol Generator System, before starting the measurements and Connect the Spike Guard to Photometer. | ||||
| 5.3.3 | Start the air to generate the aerosol particles of PAO at 20 psi pressure by using Aerosol Generator System. | ||||
| 5.3.4 | Direct the generator face to the return air point or fresh air intake of the LAF. | ||||
| 5.3.5 | Connect one end of the tube to filter face upstream port and another end to Photometer in Downstream port. | ||||
| 5.3.6 | Switch ON the photometer and set it to zero. | ||||
| 5.3.7 | Put the photometer to upstream mode and visually note the reading on display, the reading should be in between 20 mg/Ltr to 80 mg/Ltr. | ||||
| 5.3.8 | If it is between the above range then set the value to 100%, wait until the photometer displays 100% upstream concentration. | ||||
| 5.3.9 | Switch ‘ON’ the photometer, enter the clear mode and enter zero. Wait until photometer display shows ‘0’ (zero). | ||||
| 5.3.10 | Change photometer mode to downstream mode and scan the entire filter by holding the probe approximately one inch away from the filter face. | ||||
| 5.3.11 | Scan the corners of HEPA filter for checking any leakages. | ||||
| 5.3.12 | If the reading on the photometer is more than 0.01%, rectify the leakages by tightening the locking bolts. | ||||
| 5.3.13 | Repaired patches on filters should not exceed maximum of 5% of the total filter face area and the maximum width x length of each patch should not be more than 1.5 inches. | ||||
| 5.3.14 | Total number of patches should not exceed 5 numbers / filters. | ||||
| 5.3.15 | Note down the final readings after rectification. | ||||
| 5.3.16 | If the reading on the Photometer is more than 0.01% or total number of patches exceed 5 numbers per filter, then HEPA Filter Integrity Test fails. | ||||
| 5.3.17 | Replace with new HEPA Filter and carry out PAO Test again. | ||||
| 5.3.18 | Acceptance Criteria: During scanning, percentage of the PAO penetration shown by photometer should be less than 0.01% throughout the filter. | ||||
| 5.4 | 2. Air Flow Velocity: Unidirectional Airflow | ||||
| 5.4.1 | Switch ‘ON’ Anemometer for measuring Air Velocity before starting the measurement. Use Vane type anemometer. | ||||
| 5.4.2 | 1 Filter face Air Velocity should be measured at distance of about 150 mm. | ||||
| 5.4.3 | Switch ‘ON’ the LAF air flow, place the Anemometer in front of the filter surface at a distance of about 150 mm. Check the air velocity readings at the four corners and centre. Note readings as 1, 2, 3, 4, and 5 on annexure no. 01.
Refer below figure. 1 4
2 3 |
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| 5.4.4 | Measuring time at each position should be at least 10 seconds. Record the average, maximum and minimum values. Note down the readings in annexure. | ||||
| 5.4.5 | Acceptance Criteria: The measured average velocity for each filter shall be within 0.36m/s to 0.54 m/s as per ISO-14644. | ||||
| 5.5 | 3. Non- Viable Particle Count test.: | ||||
| 5.5.1 | The test method specifies the measurement of air borne particle concentration with size distributions between 0.5µm and 5.0µm. | ||||
| 5.5.2 | Measurements can be made in any of three states as-built, at-rest and operational. | ||||
| 5.5.3 | LAF Comes under ISO CLASS 5 Classifications.
At rest the particles should not exceed 3520 (0.5µm) size and 29 (5 µm) size for compliance of LAF for Non- Viable Particle Count test. |
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| 5.5.4 | Switch ‘ON’ the LAF for 2 hours before starting the measurements. | ||||
| 5.5.5 | Connect the Spike Guard to particle counter and set the Particle counter at center position or as per the the working level of LAF. | ||||
| 5.5.6 | Position the sampling probe vertically upward. | ||||
| 5.5.7 | Switch ‘ON’ the Particle Counter and adjust the Particle Counter for ‘0’ display. | ||||
| 5.5. 8 | Start taking readings of LAF and take print of the reading. Take at least 3 readings from same position in LAF. Refer ISO-14644 for the test. | ||||
| 5.5.9 | Thermal paper print should be pasted on a blank page and should be Photocopied immediately. | ||||
| 5.5.10 | Record validation data on Annexure. | ||||
| 5.5.11 | Acceptance Acceptance Criteria: The LAF should meet the criteria as per ISO Class 5 classifications i.e. NMT 3520 particles/m3, for particles size equal to or greater than 0.5 µm and NMT 29 particles/m3 for particles size equal to or greater than 5 µm. | ||||
| Frequency – Yearly by External agency | |||||
| 5.5.12 | After the test is completed, the LAF and the surrounding areas shall be cleaned properly. | ||||
| 5.5.13 | If the validation study fails, file an deviation, rectify the problem and again validate the LAF. | ||||
- Definitions / Abbreviations :
- Definitions :
- Abbreviations :
| Abbreviation | Expansion |
| ISO | International Standard Operating |
| RLAF | Reverse Laminar Air Flow |
| LAF | Laminar Air Flow |
| AHU | Air Handling Unit |
| psi | per square inch |
| HEPA | High efficiency particulate air |
| PAO | Poly Alfa Olefin |
| mg | milligram |
| % | percent |
| lts | litres |
| IPA | Iso Propyl Alcohol |
| ft | feet |
| avg | average |
| μm | micrometer |
*Note – Ready to use SOP available in “DOWNLOAD” Section.