Guide to Inspections of High Purity Water Systems
💧 Guide to Inspections of High Purity Water Systems
1. System Design & Qualification
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✅ Is the system designed with sanitary construction (316L SS, orbital welding, sloped piping, drainability)?
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✅ Has the water system undergone DQ, IQ, OQ, and PQ?
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✅ Are P&IDs and system drawings approved and updated?
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✅ Is there evidence of risk assessment for microbial control (dead legs < 1.5 × pipe diameter, no stagnant points)?
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✅ Are storage tanks vented with hydrophobic filters and fitted with spray balls for CIP/SIP?
Key Audit Focus: Improper design, dead legs, lack of documentation.
2. Operation & Maintenance
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✅ Are SOPs in place for operation, sanitization, and maintenance?
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✅ Is routine preventive maintenance performed and documented?
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✅ Are pumps, valves, and instruments maintained in sanitary condition?
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✅ Is there a defined frequency for heat sanitization or chemical sanitization?
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✅ Is re-circulation continuous to avoid stagnation?
Key Audit Focus: Irregular sanitization, improper maintenance logs.
3. Calibration & Instrumentation
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✅ Are online instruments (TOC, conductivity, temperature, pressure) calibrated as per schedule?
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✅ Are calibration records traceable to national/international standards?
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✅ Are alarms for excursions in place and functional?
Key Audit Focus: Expired calibrations, non-functional alarms.
4. Water Quality Monitoring
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✅ Is sampling done at representative points (POUs, tank, loop, return line)?
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✅ Are chemical, microbiological, and endotoxin tests performed as per pharmacopeial requirements (USP/EP/JP/IP)?
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✅ Are trending reports prepared (conductivity, TOC, microbial counts)?
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✅ Is alert and action limit rationale documented scientifically?
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✅ Are OOS/OOT investigations performed promptly?
Key Audit Focus: No trending, arbitrary limits, poor documentation.
5. Microbial Control
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✅ Is the system maintained at >65°C (hot PW/WFI) or equivalent sanitization regime?
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✅ Are biofilm control strategies documented (heat/chemical sanitization)?
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✅ Are microbial excursions investigated thoroughly?
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✅ Is there an action plan for repeated contamination?
Key Audit Focus: Uninvestigated excursions, biofilm formation.
6. Documentation & Data Integrity
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✅ Are logbooks for operation, sanitization, and maintenance complete and contemporaneous?
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✅ Are electronic data (TOC, conductivity) secured with audit trails?
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✅ Is there traceability from sampling to test results?
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✅ Are deviations and CAPAs documented properly?
Key Audit Focus: Missing log entries, shared logins, incomplete deviation reports.
7. Regulatory Compliance & Validation
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✅ Are protocols and reports for system qualification approved by QA?
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✅ Has validation been performed for seasonal variations?
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✅ Are periodic requalification and validation reviews documented?
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✅ Is the system compliant with USP <643> TOC, <645> Conductivity, <1231> Water guidance?
Key Audit Focus: Validation gaps, non-compliance with pharmacopeia.
📌 Common Deficiencies Found by Inspectors
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Dead legs or poorly designed piping.
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Inadequate sanitization frequency.
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Missing or incomplete logbooks.
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Sampling not representative of the entire system.
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OOS/OOT results not investigated.
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Outdated system drawings/P&IDs.
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Lack of trending and risk assessment.
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