Standard Operating Procedure for Cleaning Storage Tanks Used for Bulk Gel
| Department | Gel Manufacturing |
|---|---|
| SOP No. | SOP/GM/058/2025 |
| Supersedes | SOP/GM/058/2022 |
| Page No. | Page 1 of 11 |
| Issue Date | 02/06/2025 |
| Effective Date | 04/06/2025 |
| Review Date | 02/06/2026 |
1. Purpose
To establish a standardized procedure for the cleaning of stainless steel storage tanks used for storing bulk gel formulations to prevent contamination and maintain compliance with Good Manufacturing Practices (GMP).
2. Scope
This SOP applies to all vertical or horizontal storage tanks used
to hold intermediate or finished bulk gel products prior to packaging in the Gel Manufacturing Department.
3. Responsibilities
- Production Operator: Responsible for performing the cleaning activities as per procedure.
- Maintenance Team: To assist in disconnection and utility checks during cleaning.
- Quality Assurance: Verifies cleaning effectiveness and ensures compliance.
4. Accountability
The Department Head of Gel Manufacturing and the Head of QA are jointly accountable for adherence to this SOP.
5. Procedure
5.1 Pre-Cleaning Preparation
- Ensure that the storage tank is empty and disconnected from filling lines if applicable.
- Check for any physical damage, residues, or spills around the tank.
- Wear the appropriate PPE: gloves, goggles, and chemical-resistant aprons.
- Place “Cleaning in Progress” signage near the work area.
5.2 Manual Cleaning Steps
- Rinse the tank with ambient temperature purified water to remove bulk residues.
- Apply a validated cleaning solution (e.g., 2% NaOH) using a spray ball or manually with soft brushes.
- Allow the solution to circulate for a minimum of 15 minutes or as per cleaning protocol.
- Drain the cleaning solution completely and inspect the tank surface.
- Rinse thoroughly with purified water until rinse water conductivity is within acceptable range (<10 µS/cm).
5.3 Final Rinse and Drying
- Use Water for Injection (WFI) for a final rinse if product requires higher cleanliness level.
- Dry the tank using filtered air or allow it to air dry in a controlled environment.
5.4 Cleaning Frequency
- After each batch transfer to filling or packing.
- After product changeover.
- If idle for more than 72 hours without nitrogen blanketing.
5.5 Cleaning Verification
- Swab samples to be collected from internal tank walls, nozzles, and manholes.
- Perform Total Organic Carbon (TOC) or visual inspection as per cleaning validation protocol.
- QA to review and sign off the results prior to reuse of the tank.
6. Abbreviations
- SOP: Standard Operating Procedure
- PPE: Personal Protective Equipment
- QA: Quality Assurance
- WFI: Water for Injection
- TOC: Total Organic Carbon
7. Documents
- Tank Cleaning Log – Annexure-1
- Swab Sampling and Verification Form – Annexure-2
8. References
- WHO GMP Guidelines
- Schedule M – Cleaning Procedures
- Internal Cleaning Validation Protocol
9. SOP Version
Version: 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | |||
| Designation | Jr. Production Chemist | QA Executive | Head – Manufacturing |
| Department | Gel Manufacturing | Quality Assurance | Manufacturing |
11. Annexures
Annexure-1: Tank Cleaning Log
| Date | Tank ID | Cleaning Agent | Rinse Conductivity (µS/cm) | Drying Method | Operator | QA Verified |
|---|---|---|---|---|---|---|
Annexure-2: Swab Sampling and Verification Form
| Sample Point | Swab No. | Result (TOC/Visual) | Limit | Pass/Fail | QA Sign |
|---|---|---|---|---|---|
| Tank Wall | <2.0 µg/cm² | ||||
| Nozzle | <2.0 µg/cm² | ||||
| Manhole | <2.0 µg/cm² |
Revision History
| Revision Date | Revision No. | Details | Reason | Approved By |
|---|---|---|---|---|
| 01/06/2022 | 1.0 | Initial version | New SOP Creation | QA Head |
| 02/06/2025 | 2.0 | Added TOC limits and detailed annexures | Regulatory Alignment | QA Head |