Surface swab tests

1. Purpose:-

To determine the efficiency of routine cleaning procedures and to evaluate that area is free from any contamination that permits the microbial growth.

2. Scope:-

This procedure is applicable to sterile surfaces and equipments present in clean rooms of Liquid Injectable and IV Infusion filling areas of Production department and Sterility Testing Suit of Microbiological Lab.

3. HSE Statement:-

Proper gowning technique should be followed.

4. Responsibilities:-

i) Manager Quality Control is responsible to ensure that procedure & formats are followed entirely as approved.

ii) Microbiologist is responsible to perform the swab test.

iii) Lab attendant is responsible to assist the officer microbiologist for the preparation of test materials.

5. Materials:-

5.1 Sterile cotton swabs in a sterile container

5.2 Small Test tubes containing 10ml sterile 0.9% NaCl saline solution.

5.3 Sterile Petri plates

5.4 Flask containing autoclaved tryptic soya agar

6.5 Test tube rack

5.6 Disinfectant (70% IPA) Spray

5.7 Stainless Steel Tray

6. Definitions:-

6.1 Swab test

A test to determine the microbial status of regular as well as irregular surfaces of sterile areas .Swabs are devices provided used to sample surfaces for the determination of microbial status. The swabs generally composed of a stick with an absorbent extremity, is moistened before sampling and used to sample a specified unit area of a surface.

7.0Flow Chart:-

8.0 Description:-

8.1 Procedure:-

8.1.1 Preparation of material for Swab test

8.1.1.1 Take thin SS-rod and wrap firmly a thin layer of cotton on it.

8.1.1.2 Place the cotton swabs in a suitable container.

8.1.1.3 Dispense 10ml 0.9% NaCl saline solution in small test tubes and places them in test tube rack.

8.1.1.4 Cover the test tube rack with the aluminum foil

8.1.1.5 Autoclave all the materials at 121⁰C for 15 minutes.

8.1.1.6 Place the mopped SS-tray containing the material in pass through of the clean room to be tested

under UV light.

8.1.2 Procedure of taking Swab sample

8.1.2.1 Before taking sample of any surface, ensure that the surface is dry.

8.1.2.2 For each surface to be tested, swab should be removed from container under laminar air flow hood (LFH).

8.1.2.3 After removing swab, dip it in labeled test tube containing 0.9% NaCl sterile solution.

8.1.2.4 Wipe the swab over the sample area in close parallel streaks, using firm even pressure and rotating the swab between fingers to maximize the sample pick up.

8.1.2.5 The swab should be held at a 30⁰ angle to contact surface.

8.1.2.6 With the same swab, repeat the process at right angles to first streaks to ensure that the

entire sample area is swabbed.

8.1.2.7 Place the swab in 0.9% NaCl sterile saline solution in which it is previously dipped.

8.1.2.8 Area covered by a single swab should be 25 to 30cm².

8.1.2.9 Test is performed starting from most critical place i.e.; machine parts to least critical surfaces.

8.1.2.10 Those areas which are not easily accessible must be properly tested by inserting swabs in the crevices.

8.1.2.11 After taking the swab, gather all the samples and place them in SS-tray.

8.1.2.12 Transfer the SS-tray to Microbiological Lab.

8.1.3 Plating out method for swab samples

8.1.3.1 Samples should be plated under LFH

8.1.3.2 Label the empty sterilized Petri plates on their lid side according to area from where

sample is taken

8.1.3.3 Aseptically open the swab tube and pour the whole content of the tube in the Petri plate

8.1.3.4 Take the sterile flask containing autoclaved molten agar cooled at 40⁰C and pour about 30ml of agar in each Petri plate containing swab samples.

8.1.3.5 Rotate the Petri plate once clock wise and once anti clockwise to mix its content.

8.1.3.6 Swab should be plated out as soon as possible after sampling. If there is delay, the swab should be stored at room temperature, but not more than 2 hours

8.1.3.7 A negative swab control should also be plated. Negative swab control will not contain any sample.

8.1.3.8 Incubate the Petri plates at 32.5+2.5ºC for 48 -72hours and record

8.2 Specifications:-

For each grade of controlled areas or clean rooms microbial limits are given below.

Table: Limits* for Microbial contamination (cfu/25cm²)^‡

Sr. No.	Grade / Class	At rest (cfu/25cm²)	Operational (cfu/25cm²)
1	A	<1	NMT 3
2	B	<1	5
3	C	5	25
4	D	25	50

· Limits are bacterial count. Mold or fungal count should be considered as zero.

8.3 Frequency:-

Monthly and after a shut down for a week or more

9. Records

9.1 Surface Swab Test Report

9.2 Area Monitoring of Sterility Testing Room

10. Reference:

10.1 United States Pharmacopoeia 35.

10.2 Guidelines on the Test Methods for Environmental Monitoring for Aseptic Dispensing Facilities, Produced by: A Working group of the Scottish Quality Assurance Specialist Interest Group, February 2004.(For All Classes at Rest and Operational B, C and D)

Monthly and after a shut down for a week or more