SOP for Calibration of UV Cabinet

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SOP for Calibration of UV Cabinet

1. Purpose

To establish a procedure for calibration and performance verification of the UV cabinet to ensure effective UV radiation for microbial control and compliance with GMP requirements.

2. Scope

This SOP applies to all UV cabinets used in the microbiology laboratory and other controlled areas for sterilization/disinfection purposes.

3. Responsibility

  • Microbiology/QC Analyst: Perform calibration and record results
  • Quality Assurance (QA): Review and approve calibration records
  • Engineering/Maintenance: Maintain UV cabinet and replace UV lamps if required

4. Definitions

  • UV Cabinet: Enclosed chamber fitted with UV lamps used for surface sterilization
  • UV Intensity: Measurement of UV radiation, typically expressed in µW/cm²
  • Lux Meter / UV Radiometer: Instrument used to measure UV intensity

5. Procedure

5.1 Frequency of Calibration

  • Calibration shall be performed:
    • Initially (after installation)
    • Every 6 months (or as per SOP requirement)
    • After replacement of UV lamp
    • After major maintenance

5.2 Instruments Required

  • Calibrated UV Radiometer / UV Intensity Meter
  • Stopwatch
  • Calibration record format

5.3 Pre-Calibration Checks

  • Ensure UV cabinet is clean and free from dust
  • Check UV lamp for physical damage or blackening
  • Switch ON the UV lamp and allow warm-up for 10–15 minutes

5.4 Measurement of UV Intensity

  • Place the UV radiometer sensor at different locations inside the cabinet:
    • Center
    • Corners (all four sides)
  • Record readings at each location
  • Take at least 5 readings for uniformity assessment

5.5 Acceptance Criteria

  • UV intensity should be ≥ 40 µW/cm² (or as per internal specification)
  • Uniform distribution across cabinet
  • Any reading below limit indicates inadequate sterilization

5.6 Action in Case of Failure

  • Replace UV lamp if intensity is below acceptance criteria
  • Recalibrate after replacement
  • Document deviation and corrective action

5.7 Documentation

  • Record the following:
    • Date of calibration
    • Instrument ID and calibration status
    • UV intensity readings
    • Analyst name and signature
    • QA approval

6. Precautions

  • Do not expose skin or eyes to UV radiation
  • Always switch OFF UV lamp before opening cabinet
  • Use PPE (gloves, lab coat, UV-protective goggles if required)

7. References

  • WHO GMP Guidelines
  • Schedule M (India)
  • ISO guidelines for laboratory equipment calibration

8. Annexures

Annexure I: UV Cabinet Calibration Record

Date Cabinet ID Location UV Intensity (µW/cm²) Acceptance (Pass/Fail) Remarks

Annexure II: Calibration Checklist

  • UV lamp condition checked
  • Warm-up time followed
  • Radiometer calibrated
  • Readings recorded at all points
  • Acceptance criteria met
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