Requalify HVAC Systems on Schedule to Maintain Environmental Control

Perform Scheduled Requalification of HVAC Systems in GMP Areas

Remember: HVAC systems in cleanrooms must be requalified periodically to maintain airflow, pressure differentials, and contamination control.

Why This Matters in GMP

HVAC systems play a pivotal role in maintaining the cleanliness, temperature, humidity, and pressure gradients of pharmaceutical production environments. Over time, filters degrade, ducts accumulate particulates, and airflows may deviate from design parameters. Without periodic requalification, these changes may go unnoticed and compromise environmental control. This can lead to microbial growth, cross-contamination, or out-of-specification environmental conditions. Requalification ensures that the HVAC system performs as intended and supports batch integrity, especially in sterile or classified manufacturing zones. Skipping this critical validation step could risk batch failure or product recall due to unseen environmental deviations.

Also Read: How to Achieve GMP Compliance for Clinical Trial Supplies and Investigational Products

Regulatory and Compliance Implications

EU GMP Annex 1, FDA 21 CFR Part 211.42 and 211.46, and Schedule M mandate regular HVAC system requalification. WHO GMP requires periodic testing of cleanrooms and associated HVAC systems. Regulatory auditors scrutinize qualification protocols, frequency, results, and deviations. Lack of requalification or outdated records can lead to critical audit observations. Agencies expect particulate monitoring, HEPA filter integrity tests, airflow mapping, and pressure differential verifications during requalification. These records must be traceable, reviewed by QA, and linked to facility control strategies.

Implementation Best Practices

Establish a documented HVAC requalification schedule (e.g., every 6–12 months depending on risk).
Perform temperature, RH, pressure differential, and particulate monitoring across all classified zones.
Conduct HEPA filter leak tests and airflow velocity mapping using validated instruments.
Involve third-party HVAC experts if required and retain qualification reports with version control.
Link requalification outcomes to risk assessments and preventive maintenance plans.

Also Read: Implement Controlled Access to Data Entry Terminals in GMP Areas

Regulatory References

FDA 21 CFR Part 211.42 – Design and Construction Features
FDA 21 CFR Part 211.46 – Ventilation, Air Filtration, Air Heating and Cooling
EU GMP Annex 1 – Manufacture of Sterile Medicinal Products
WHO GMP – HVAC and Cleanroom Validation
Schedule M – Air Handling System Requirements