SOP for Environmental Monitoring by Settle Plate Method

Purpose

This SOP is provide written guidelines for exposing sterile Soyabean casein digest agar & Sabouraud Chloramphenicol agar plates to enumerate the bioload of classified & non- classified areas.

Scope

This SOP extends to all departments like Tablets, Liquid orals, Dry syrup & Microbiology Departments.

Responsibility

Q.C. Microbiologist

Procedure

Media Used:

• Soya bean casein digest agar.
• Sabouraud Chloramphenicol agar.

For details of Media composition and preparation refer SOP for Preparation of Culture Media

Preparation of Plates:

• Plates used: Disposable Gamma sterilized plates 90 mm dia.
• Switch on the Laminar airflow.
• Clean the laminar flow table with 70% v/v IPA.
• Cool the sterilized media to about 45°C.
• Remove the cotton plug of the sterilized media flask near the flame and hold it along with the flask in the right hand.
• Hold the mouth of the flask near the flame slanting taking care the contents do not spill out.
• Take out a sterile Petri plate using left hand and open the lid slightly near the flame.
• Carefully pour about 15 to 20 ml of media to each plate
• Close the plate and place it on the laminar bench.
• Allow it to solidify.
• Repeat the steps 7 to 10 till the media gets over.
• Mark the plate with media name and its allotted Rehydrated media B. No.
• Incubate the SCDA plates at 30° to 35°C for 48 hours before use.
• Incubate the SCA plates at 20° to 25°C for 48 hours before use.

Method of exposure:

• Identify each pre-incubated SCDA & S C A plate with the location to be exposed along with a date. Refer to ANNEXURE-1 for locations to be monitored.
• Carry these plates in a stainless steel bin previously wiped with IPA 70% v/v to the respective department. (during the activities are going on)
• Follow the gowning procedure as required by the respective department to avoid additional contamination.
• Disinfect the hands with IPA 70%v/v, and wear sterile surgical gloves.
• Place the Petri plates with their lid still covering the media at predetermined
• points of monitoring.
• Remove the lid of the Petri plate and rest it on the rim of the Petri plate base where by maximum exposure of agar surface is made.
• Expose the SCDA & SCA plates for 1 hour and replace the lids on the respective plates carefully.
• Collect all the plates in the stainless steel bin wiped with 70%v/v IPA & bring it to the Microbiology department.
• Incubate all the S C D A plates inverted at 30° to 35°C in an incubator for 72 hours.
• Incubate all the S C A plates inverted at 20° to 25°C in a BOD incubator for 120 hours.
• After incubation, observe the counts and report results in the prescribed format (one format copy of each is attached)

Area

Tablets

Liquid orals

Dry syrup

Microbiology

Frequency:

Once in a week.

ALSO READ: Validation Protocol for Aseptic Media Fill

Limits:

1. Manufacturing Area

Bacteria (cfu/plate) 

• Standard Limit: NMT 100 
• Action Limit: MT 50 
• Alert Limit: MT 30

Fungi(cfu/plate) 

• Standard Limit: NMT 25 
• Action Limit: MT 15 
• Alert Limit: MT 10

2. Packing Area

Bacteria (cfu/plate) 

• Standard Limit : NMT 100 
• Action Limit : MT 65 
• Alert Limit : MT 50

Fungi(cfu/plate) 

Standard Limit : NMT 25 

Action Limit: MT 20 

Alert Limit : MT 15

(MT= More than, NMT = Not more than)

• Trends to be plotted with standard, action and alert limits are defined. Identify the organism based on the high counts and colony morphology by Gram’s staining.
• Frequency of Identification: Once in a month.

Action plan count exceeding the alert limit

During routine monitoring if the environment count exceeds the alert limit on 60% of the plates exposed in that area.

• QA department, Production department, and maintenance department should be informed.
• Increase the frequency of monitoring.
• If the contaminant levels are seen consistent or increase, advise for cleaning & of the area as per SOP.
• Expose the settle plates and monitor frequently till the environment count comes below alert limit.
• During this period production activity will be continued.

Action plan count exceeding action limit

During routine monitoring, if the environment count exceeds the action limit (in any one plate or more) the following actions are to be taken.

• QA department, Production department, and maintenance department should be informed.
• Carry out the area cleaning as per the cleaning schedule and increase the frequency of monitoring till the count comes below the alert limit.
• During this period production activity will be continued.
• If the environment count is increasing, the frequency of cleaning must be increased and continuous monitoring for environment count by settle plates must be carried out till the level comes below alert limit.

Action plan count exceeding the standard limit

During routine monitoring, if the environment count exceeds the  standard limit (in any one plate or more) the following actions are to be taken

• QA department, Production department, and maintenance department should be informed.
• Inform the manufacturing department to stop activity in that particular area.
• Increase the frequency of monitoring, investigate the cause, and carry out the fumigation
• Monitor the environment count till the bioload level comes below the alert level.
• Recheck the bioload of all products, that were manufactured during the last two checks drawing extra samples in order to evaluate the effect on a product.
• A thorough investigation must be carried out for the route cause of increase in Bioload.

Destruction of the exposed plates:

The exposed plates should be autoclaved in an Autoclave for destruction after the results are taken and then disposed off.

Annexure

Nil

Revision History

Nil

ALSO READ: SOP for Air Settling Plates Technique