SOP for Calibration of Autoclave by Indicators
Learn how to write a SOP for calibration of autoclave in pharmaceutical labs using biological indicators.
1. PURPOSE
This describes the procedure for the calibration of an autoclave using biological indicators to ensure sterilization efficacy in compliance with pharmaceutical quality standards.
2. SCOPE
This SOP is applicable to all personnel responsible for the calibration and validation of autoclaves in the pharmaceutical laboratory.
3. RESPONSIBILITIES
3.1 Microbiologist is responsible for execution of calibration activities as per this SOP.
3.2 Quality Assurance (QA) personnel are responsible for review and approval of calibration results.
3.3 Maintenance personnel are responsible for ensuring the autoclave is in proper working condition.
4. ACCOUNTABILITY
Head of the concern Department
5. ASSOCIATED DOCUMENTS/REFERENCE
5.1 Manufacturer’s instructions for biological indicators
5.2 SOP for Operating Procedure of Autoclave
6. PRECAUTIONS
6.1 Wear appropriate personal protective equipment (PPE), such as gloves and safety goggles, when handling reagents.
6.2 After the autoclave cycle is complete, allow the biological indicators to cool down to room temperature before handling them. Avoid abrupt temperature changes to prevent damage to the indicator.
6.3 Check the physical condition of the biological indicators for any signs of damage, leakage, or contamination. Discard any compromised indicators as per the disposal SOP.
6.4 If using a self-contained biological indicator (e.g., ampoule or tube with spore strip and growth media), activate it by breaking or crushing the inner ampoule as per the manufacturer’s instructions. This step releases the growth medium onto the spores.
6.5 Clearly label the biological indicators with relevant details such as the date, time, autoclave batch number, and any other required information for traceability.
6.6 Ensure that the incubator maintains consistent temperature and environmental conditions. Verify the calibration of the incubator periodically as per the SOP.
6.7 Monitor the biological indicators during the recommended incubation period (usually 24–48 hours). 6.8 Record any color changes, turbidity, or other signs of microbial growth.
6.9 After incubation, autoclave all used biological indicators again to neutralize any potential microbial growth before disposal. Follow the waste disposal SOP to discard them safely.
7. PROCEDURE
7.1 Materials and Equipment
-Biological indicators (spore strips or self-contained BIs)
-Sterile forceps or tweezers
-Autoclave with temperature and pressure gauges
-Incubator suitable for the BI’s growth conditions
-Sterile gloves
-Sterile petri dishes
-Recording logbook
7.2 Verify the cleanliness and operational readiness of the autoclave.
7.3 Check the expiration date and storage conditions of the biological indicators.
7.4 Ensure the incubator is functional and set to the appropriate conditions for the BI.
7.5 Place the biological indicators in representative locations within the autoclave. These typically include:
-Center of the load
-Corners of the chamber
-Near the autoclave drain
7.6 Use sterile forceps and gloves to handle biological indicators.
7.7 Run the autoclave at the standard sterilization cycle (e.g., 121°C for 15 minutes or as per your validated parameters).
7.8 Record the temperature, pressure, and cycle duration.
7.9 Allow the autoclave to complete the cycle and cool before opening.
7.10 Remove the biological indicators using sterile techniques.
7.11 Place the indicators in the incubator as per the manufacturer’s instructions (e.g., 55–60°C for Geobacillus stearothermophilus).
7.12 Include a positive control (unexposed BI) to confirm the viability of spores.
7.13 Incubate for the recommended duration (e.g., 24-48 hours).
7.14 Observe the indicators for color change or turbidity (for self-contained BIs) or spore growth (for spore strips).
7.15 Record the results:
-No growth or color change: Pass (sterilization effective)
-Growth or color change: Fail (sterilization ineffective)
7.16 Record all calibration activities in the autoclave calibration log.
7.17 Include details of the cycle parameters, BI results, and any corrective actions taken.
7.18 Perform calibration annually or after any major maintenance or repair of the autoclave.
7.19 Perform routine checks during regular sterilization cycles.
7.20 Corrective Actions
7.20.1 If any indicator shows growth, investigate potential causes (e.g., incorrect loading, equipment malfunction).
7.20.2 Recalibrate or repair the autoclave as necessary.
7.20.3 Repeat the validation cycle with new BIs.
8. ABBREVIATIONS / DEFINITIONS
8.1 Calibration: The process of adjusting and verifying the instrument’s accuracy and performance to ensure it provides correct and consistent results.
8.2 QA: Quality Assurance
8.3 SOP: Standard Operating Procedure
8.4 BIs: Biological Indicators
8.5 QC: Quality Control
8.6 PPE: Personal Protective Equipment
9. ANNEXES
9.1 Annex-1: Log Book for Calibration of Autoclave
10. Revision History
| Version | Date | Description of Change | Reviewed By | Approved By |
| 1.0 |