STANDARD OPERATING PROCEDURE Title: Air Sampling of Sterile Area

1. Scope

To measure the air contamination level of sterile area.

2. Principle

Based on impaction of microorganism or against medium followed by incubation
and colony counting

3. Purpose

This is to find the nature and source of the contamination by counting the CFU (colony forming unit) on the Petri dish

4. Responsibilities

1. Manager Q.C
2. Microbiologist.

5. Procedure

1. Follow up all the instruction personal entering in sterile area process and hold the “ON/OFF” key for one section.
2. From the main screen, press the right arrow once to access the setting menu, to have access to the function proposed in the setting menu, choose language, back light setting.
3. Select sample menu, then select “create” (when change require) by directional arrows select either volume/time.
(Can enter the volume in liters from 100 to 999 lit),
(Can enter the time from 1 to 99 minutes)
Finally press the enter button if the program already exist, a tone will
found. Return to the previous screen by previous by pressing “ESC” selected program can be delete using directional arrows and then press “enter”.





4. Select the delay time using directional arrows then press “enter”. We can modify minutes; second by pressing enter (range from 00:00 to 59:59) the deactivation is made by dialing 00:00.
The count down time allow to enter a time valve that start count down as soon as we have pressed the enter key and when the time is up the sample collection start.
5. Mopp the outer surface of sampler.
6. Remove the “SS” grid from the block by pulling up and fix the Petri dish on the clips and make sure that the Petri dish is place horizontally (Petri dishes should wrapped in aluminum foil S.S closed box)
7. Fix the sterilized sampling head (i.e autoclaved at 121ºC for 15 min. The device measures the incoming air flow and regulates the aspired air to a constant flow rate of 100 liters /min the impaction velocity on the agar is 16.8 m/s.
8. Start sample collection by pressing “start button” or by using the remote control.
9. At the end of the sampling period (the set value is displayed after a short message (end of sampling)
10. Remove the impaction grid and close the Petri dish mention specific area over it and incubate in for 72 hrs at 30-35ºC. At the end of the incubation it will be possible to count the CFU/m3.

6. Counting and Calculation:

After incubation the level of air born contamination can be calculated using formula.
= N
V
When n is the probable number of viable impacted particles either estimated or adjusted.

To calculate “N” count the number “N” of CFU (colony forming unit) which have grown then consults the correspondence in appendices section. A table indicates the “n” value (number of colonies actually numerated) corresponding to “N” (probable number of viable impacted particles-either estimated or adjusted)

Once N is identified then controlled volume “V” can be calculated by formula.
V=sampling duration x 0.1m3/min]
Example:
After sampling and incubation 120 colonies are4 counted on Petri dish then.
n = 120
N = 161
V = 5 min x 0.1 m3 /min = 0.5m3
So
Level of air born contamination = 161 =322 CFU/m3
0.5
7. Limits for different classes

Class Limit
1 0 CFU / m3
2 10 CFU / m3
3 100 CFU / m3
4 1000 CFU / m3

8. Precautions:

1. To prevent fore or shock hazard do not expose this device to rain or humidity.
2. Clean & mop thoroughly before and after the sample collection because wide range of stains can contamination the sampling and can reduce the reliabilities of the results.
3. External surfaces and the sampling grid should be sprays e a disinfectant or IPA sol during more than one sampling.