SOP FOR Operation, Cleaning and Monitoring of Laminar Air Flow

SOP FOR Operation, Cleaning and Monitoring of Laminar Air Flow

1.0       OBJECTIVE

To lay down a standard procedure to perform the operation, cleaning and monitoring of Laminar Air Flow.

2.0       SCOPE

This Standard Operating Procedure is applicable for Laminar Air Flow which is installed in Microbiology laboratory of Quality Control Department.

Instrument ID: —————————————

Make             : ————-


            Microbiologist shall be responsible to follow the procedure mentioned in this SOP.


Department Head & QA Head shall be accountable for implementation & compliance of this SOP.


Format for the record of Manometer pressure & UV lamp burning hours of LAF     – Attachment-I

Format for the record of daily monitoring of LAF                                                            – Attachment-II

6.0         PROCEDURE:

6.1           Precautions

6.1.1        Do not switch ON the UV light during working period.

6.1.2        Do not start work immediately after switching ‘OFF’ the UV light.

6.1.3        Handle the media, cultures and samples carefully while working on LAF bench.

6.2           Operation

6.2.1        Ensure that all the electric connections of the LAF are properly connected.

6.2.2        Ensure that the equipment is in clean state.

6.2.3        Switch ‘ON’ the main power supply.

6.2.4        Switch ‘ON’ the UV light for 15 minutes.

6.2.5        Switch ‘OFF’ UV light after 15 minutes and maintain record for UV lamp burning hour as per


6.2.6        Start blowers 15 minutes prior to the operation.

6.2.7        Check and ensure the manometer reading between 10 to 15 mm water gauge and record the readings

As per attachment-I.

6.2.8        Mop the laminar flow bench and side walls with 70% Isopropyl alcohol using sterile lint free cloth.

6.2.9        Start the requisite microbiology work.

6.2.10      After completion of work, wipe the LAF bench and side walls with 70% IPA Solution using sterile

lint free clean cloth and switch ‘ON’ UV light for 15 minutes.

6.2.11      After 15 minutes switch ‘OFF’ the main power supply.

6.2.12      Periodic validation of LAF should be performed once in a year by outside agency and records should

be maintained.

6.3           Cleaning

6.3.1        Keep the laminar air flow interior and exterior free from dust.

6.3.2        Clean the interior of LAF with 70% IPA using sterile lint free cloth before starting the work and

after completing the work.

6.4           Monitoring of LAF

6.4.1        Prepare the plates of Soybean casein digest agar (for bacteria) and Sabouraud Dextrose Agar (for

fungus) as per SOP of Media preparation and sterilization.

6.4.2        Pre-incubate the plates before exposure at 30-35°C for 24 hours.

6.4.3        After pre-incubation, transfer the SCDA & SDA petriplates into pass box.

6.4.4        Enter in the respective area as per the SOP for entry and exit in MLT/assay room.

6.4.5        Collect the petriplates from pass box and decontaminate the external surface of the petriplates with

the help of a sterile lint free cloth soaked in 70% IPA solution.

6.4.6        Mark the petriplate a on the base with the following details with marker.

  •          Name of media
  •          Name of location
  •          Date of exposure

6.4.7        Place the petriplates on the bench of LAF and remove the upper lid of petriplates.

6.4.8        Expose the media plates for 4 hours.

6.4.9        After 4 hourrs of exposure, close the petriplaes with lid. Collect the petriplates and transfer into the

incubator through pass box.

6.4.10      Incubate the exposed plates in inverted position at 30-35°C for 3-5 days for bacterial growth and at

20-25°C for 5-7 days for fungal growth.

6.4.11      After incubation observe and count the number of colonies on the colony counter or in the source of

light with the help of marker.

6.4.12      Keep negative control plate without exposure in thte incubator and positive control plate by exposing

the plate in the non-sterile environment.

6.4.13      Note down the observation as per attachment-II

6.4.14     Acceptance criteria

  •       Action limit: 1 CFU/plate for both (TBC & TFC))
  •       The positive control should show growth and negative control should not show any growth.

6.4.15      If the count obtained are out of limit as per specification investigate the results and take necessary


6.4.16      Frequency of monitoring

Once in a day whenever there is activity.

7.0           REFERENCES



SOP: Standard operating procedure

%     : Percent

CFU: Colony forming unit

LAF:  Laminar air flow

°C   : Degree Celsius

I.PA  : Isopropyl Alcohol

TBC : Total bacterial count

TFC : Total fungal count

SCDA: Soyabean Casein Digest Agar

SDA  :  Sabouraud Dextrose Agar

QA  : Quality Assurance

QC  : Quality Control


Quality Assurance Department

Quality Control Department



Version Number Effective Date Reason for Revision




Title : Record of manometer pressure & UV lamp burning hours of LAF
Version No. : 00 Page No. : Page 1 of 1


Effective Date :   Review Date :  


Instrument ID No.:


Manometer UV Lamp Done By Checked By
Limit: From To Total Min.


Title : Record of daily monitoring of LAF
Version No. : 00 Page No.


: Page 1 of 1


Effective Date :   Review Date :  



Frequency: Once in a day whenever there is activity.

Acceptance criteria: Action limit: 1 CFU/plate (for both TBC & TFC)

Date of plate exposure Plate exposure start time Plate exposure end time Plates exposed by Total bacterial count (CFU/plate/4 hrs.) Total fungal count (CFU/plate/4 hrs.) Checked by








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