In a risk-based inspection (RBI), Schedule M points 4.1–4.3 (in the CDSCO RBI checklist under Water & Compressed air system) are treated as critical utility controls, because an uncontrolled water system can cause microbial/chemical contamination, endotoxin risk, and batch impact across multiple products. Schedule M also expects a validated water treatment system producing pharmacopoeial Purified Water, with storage that prevents microbiological growth and periodic tank cleaning with records. CDSCO
4.1 – Current water system drawing (from inlet to points of use)
Inspectors verify an up-to-date schematic/drawing that shows all equipment from the feed inlet through pretreatment/purification, storage, distribution loop, and every point of use. CDSCO
RBI intent: without an accurate drawing, you cannot reliably control risk-based sampling locations, identify dead-legs, manage change control, or investigate excursions. Inspectors cross-check that the drawing matches the现场 installation (sampling/user points, valves, return loop, drains), and that revisions are controlled.
4.2 – Water system validation/qualification (protocols and reports)
Inspectors verify that water system validation/qualification has been performed as per approved protocols, and that reports are prepared and maintained. CDSCO
RBI intent: confirm the system consistently delivers water meeting specs and remains in a validated state. Evidence typically includes DQ/IQ/OQ/PQ packages, commissioning records, defined monitoring plans, alert/action limits, deviation handling, sanitization/cleaning records, and trend reviews (chemical + microbiological). WHO guidance also supports a risk-based scope and a structured validation lifecycle for water systems. World Health Organization
4.3 – IQ protocol content (WHO TRS-970 expectations)
Inspectors check whether the IQ protocol includes at least: facility review, equipment specification vs design, welding roughness testing, checks for absence of dead points/sections, pipe and tank passivation, drawings, SOPs for operation/cleaning/sanitation/maintenance, and calibration of instruments, plus complete IQ report elements (summary, data tables/results, protocol references, revisions, approvals). CDSCO
Common RBI red flags: outdated drawings, missing sampling-point rationale, “qualification” without robust IQ content, weak change control after piping modifications, and poor trending/response to recurring excursions.