SOP Title: Validation of Disinfectant’s Effectiveness
- Objective:
To lay down the Procedure for Validation of Disinfectant’s Effectiveness.
- Scope:
This procedure is applicable for Validation of Disinfectant’s Effectiveness in Microbiology Section of Quality Control Department.
- Responsibility:
3.1 Quality Control: To prepare and review the SOP. To follow the Procedure for Validation of Disinfectant’s Effectiveness 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: | |
| 5.1.1 | Wear personal protective equipments such as protective hand gloves, nose masks and over gown during operation. | |
| 5.1.2 | Microbiologist should disinfect the hand gloves with 70% v/v Iso Propyl Alcohol before carrying out operation. | |
| 5.2 | Procedure of preparation of swab sample: | |
| 5.2.1 | 1. Refer SOP of Media Preparation and Sterilisation for preparation of media and solutions. | |
| 5.2.2 | Prepare a swab test sample by measure 10 ml of Buffered Sodium Chloride peptone pH 7.0 solution in a test tube. | |
| 5.2.3 | Cotton swabs are inserted in test tubes containing 10 ml buffered Sodium Chloride pH 7.0 and plugged with non absorbent cotton. | |
| 5.2.4 | Autoclave these test tubes at 1210C for 15 minutes. | |
| 5.3 | Swabbing Procedure: | |
| 5.3.1 | Before mopping, swab should be taken from an area which is difficult to clean and when in operation. Refer SOP for swabbing procedure. | |
| 5.3.2 | With the help of a Swab template, swab the 10 x 10 cm2 area of the floor by moving the swab in an zig zag motion within the template in around 10 strokes with sterile swab before mopping and dip it in the sterile buffer sodium chloride peptone solution contained in the test tube. Immediately close the mouth of the tube with cotton plug or autoclavable cap. Mix for 1 minute. Refer Annexure for Swab procedure diagram. | |
| 5.4 | Testing Procedure: | |
| 5.4.1 | Bring the test tubes in microbiology section. Carry out the Microbiology analysis for Total microbiology count & detection of pathogens. | |
| 5.5 | For Total Microbiology Count: | |
| 5.5.1 | Pipette out 1 ml of the buffered solution into empty Sterile petriplates in duplicates. Mark all details on the plates. | |
| 5.5.2 | Pour about 15 to 20 ml of Sterile Soyabean Casein Digest Agar (40- 450C) in two plate & 15 to 20 ml of sterile Sabouraud Chloramphenicol or Dextrose Agar (40- 45°C) in the remaining two plates. | |
| 5.5.3 | Mix gently and allow it to solidify. Incubate Soyabean Casein Digest Agar plate at 30-35° C for 3 to 5 days. | |
| 5.5.4 | Incubate Sabouraud Chloramphenicol or Dextrose Agar plate at 20-25 0C for 5 to 7 days. | |
| 5.5.5 | On completion of the incubation period, note down the colonies on the petriplate. | |
| 5.5.6 | For pathogen: Swab solution is streaked on selective Agar plates. Use MacConkeys Agar For E.coli, Cetrimide Agar for P. aeruginosa, Mannitol Salt Agar for S.aureus and XLDA agar for Salmonella for detection of pathogens and incubate at 30-35°C for 48 hours. Refer SOP for culture identification. | |
| 5.5.7 | Positive Controls: streaked a loopful of each of Escherichia coli, Salmonella, Pseudomonas aeruginosa & Staphylococcus aureus on selective Agar plates (as mentioned above), for detection of pathogens and incubate at 30-350C for 48 hours. | |
| 5.5.8 | Observe the colonies obtained. Test is valid only if positive control shows the Characteristic colonies. | |
| 5.5.9 | Negative Controls: Maintain a Negative control plates for each selective Agar plates i.e. MacConkey Agar, Xylose lysine deoxycholate agar, Cetrimide Agar & Mannitol Salt Agar. | |
| 5.6 | After Mopping: | |
| 5.6.1 | Mop the area and repeat the same procedure at the same area one hour after mopping with fixed concentrated disinfectant, later six hours and eight hours after mopping with selected MIC concentration solution of Dettol and Savlon, IPA sheet. Refer SOP, MIC of Disinfectants. | |
| 5.6.2 | Repeat the procedure with one disinfectant at least for 3 days for interval of 1 hour, 6 hours and 8 hours. Collect and record the Validation of Disinfectant Data in Annexure. | |
| 5.7 | Interpretation: | |
| 5.7.1 | A Reduction, not less than 85 % in the viable counts after one hour of mopping from the initial count and absence of pathogens. | |
| 5.7.2 | Not less than 70% reduction in the viable counts after Six hours and eight hours of mopping and absence of pathogens after each interval of mopping indicates that mopping with the respective disinfectant is effective. Refer Annexure. | |
| 5.7.3 | Test is valid only if positive control shows the Characteristic colonies. | |
| 5.7.4 | If the result is not within the accepted limit, then increase the concentration of respective disinfectant and carry out the Validation for increased concentration. Compile the Data in Annexure. | |
| 5.7.5 | Decontaminate all the plates and Media after completion of analysis. Refer SOP Decontamination of Microbial waste. | |
- Definitions / Abbreviations:
- Definitions
- Abbreviations:
| Abbreviation | Expansion |
| °C | Degree Centigrade |
| % | percent |
| v/v | Volume by volume |
| MIC | Minimum Inhibitory Concentration |
| IPA | Isopropyl alcohol |
*Note – Ready to use SOP available in “DOWNLOAD” Section.