Standard Operating Procedure for Cleaning and Maintenance of HEPA Filters in Cleanrooms
| Department | Sterile Injectable Manufacturing |
|---|---|
| SOP No. | SOP/SIM/057/2025 |
| Supersedes | SOP/SIM/057/2022 |
| Page No. | Page 1 of 13 |
| Issue Date | 18/06/2025 |
| Effective Date | 20/06/2025 |
| Review Date | 18/06/2026 |
1. Purpose
To define a systematic process for cleaning, maintenance, and integrity verification of HEPA filters in sterile manufacturing cleanrooms to ensure unidirectional airflow, particle control, and aseptic environment compliance as per GMP and WHO guidelines.
2.
Scope
This SOP applies to all HEPA filters installed in Grade A to D cleanroom zones within the Sterile Injectable Manufacturing facility.
3. Responsibilities
- Engineering Team: Conducts scheduled HEPA maintenance and coordinates integrity testing.
- Production Team: Ensures machine shutdown and area clearance during filter maintenance.
- Quality Assurance: Reviews reports and ensures adherence to validated procedures.
4. Accountability
The Head of Engineering is accountable for ensuring that HEPA filters are cleaned and maintained as per the defined schedule and tested for integrity as per GMP norms.
5. Procedure
5.1 Types of Maintenance
- Routine Cleaning: Surface vacuuming and external wiping of HEPA grills.
- Preventive Maintenance: Monthly airflow verification and semi-annual leak testing.
- Corrective Maintenance: Filter replacement if integrity test fails or airflow is inadequate.
5.2 Cleaning Schedule
- HEPA grills shall be cleaned weekly using lint-free cloths soaked in 70% IPA.
- Use a vacuum with HEPA-grade exhaust to remove particulate buildup on grills.
- Grills shall not be removed unless replacement or detailed internal cleaning is required.
5.3 Preventive Maintenance and Integrity Testing
- Conduct DOP/PAO challenge test for integrity every 6 months or after maintenance.
- Verify air velocity and unidirectional airflow patterns using anemometers monthly.
- Record all data in the HEPA Maintenance Log (Annexure-1).
- Replace HEPA filters if they show damage, failed test, or excessive pressure drop.
5.4 Safety Precautions
- Wear sterile PPE during HEPA filter cleaning.
- Do not touch or lean against HEPA face panels to avoid surface damage.
- Ensure cleanroom integrity by completing cleaning quickly and efficiently.
5.5 Documentation
- All maintenance activities shall be recorded in the logbook.
- QA to review and approve entries before use of area post-maintenance.
6. Abbreviations
- HEPA: High-Efficiency Particulate Air
- IPA: Isopropyl Alcohol
- QA: Quality Assurance
- GMP: Good Manufacturing Practices
- DOP: Dioctyl Phthalate
- PAO: Polyalphaolefin
7. Documents
- HEPA Filter Maintenance Log – Annexure-1
- HEPA Filter Integrity Test Report – Annexure-2
- HEPA Replacement Checklist – Annexure-3
8. References
- WHO TRS 961 Annex 6
- ISO 14644-1 and ISO 14644-3
- 21 CFR Part 211
9. SOP Version
Version: 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | |||
| Designation | Manufacturing Executive | QA Executive | Head QA |
| Department | Production | Quality Assurance | Quality Assurance |
11. Annexures
Annexure-1: HEPA Filter Maintenance Log
| Date | Room No. | Activity | Performed By | Verified By |
|---|---|---|---|---|
| 17/06/2025 | Grade B – 102 | Surface Cleaning | Rajesh Kumar | Anita Sharma |
Annexure-2: HEPA Filter Integrity Test Report
| Filter ID | Test Date | Type of Test | Result | Tested By |
|---|---|---|---|---|
| HF-203 | 10/06/2025 | DOP Test | Pass | Sunil Mehra |
Annexure-3: HEPA Replacement Checklist
| Old Filter ID | New Filter ID | Replacement Date | Installed By | QA Approval |
|---|---|---|---|---|
| HF-197 | HF-212 | 01/06/2025 | Ajay Verma | Priya Kapoor |
Revision History
| Revision Date | Revision No. | Details | Reason | Approved By |
|---|---|---|---|---|
| 01/01/2022 | 1.0 | Initial Issue | New SOP | QA Head |
| 18/06/2025 | 2.0 | Revised to include Annexure-3 checklist | Annual Review | QA Head |