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Log Plug-and-play starting point Sterility & Microbiology

Log: Water System Sampling and Results

A plug-and-play sampling and results log for a PW or WFI system: field definitions for point, conductivity, TOC, microbial, and endotoxin with alert/action flags, sampler and review fields, retention, and a filled specimen row set, with the compendial references.

Document type: Log

Read and copy the template below into your own quality system. It is a generic starting point for your own internal use, provided as is, with no warranty; see the Terms and License. Adopting it does not by itself create compliance.

This is a ready-to-use log for recording water system samples and their results against alert and action levels. It is the record the monitoring SOP generates, and the artifact an inspector reads to see whether trends were actually watched. Replace every <<FILL: ...>> placeholder, keep one row per sample, and maintain the log under document control. A field-definition table, the blank log, instructions, and a filled specimen follow. Verify each cited chapter against the current source. This is general guidance to adapt, not legal or regulatory advice. This log pairs with the SOP: Pharmaceutical Water System Sampling, Monitoring, and Excursion Response.

Log header

FieldEntry
Log number<<FILL: LOG-ID>>
System / grade<<FILL: system ID, PW or WFI>>
Alert levels (per attribute)<<FILL: e.g. microbial 3 CFU/100 mL>>
Action levels (per attribute)<<FILL: e.g. microbial 10 CFU/100 mL; TOC 500 ppb>>

Field definitions

FieldFormatRequiredWhoWhen
Sample point / IDTextYesSamplerAt sampling
Date/time sampledDate + timeYesSamplerAt sampling
ConductivityuS/cm at tempYesChemistryOn test
TOCppbYesChemistryOn test
Microbial countCFU per volumeYesMicroOn read (after incubation)
Endotoxin (WFI)EU/mLWFI onlyMicroOn test
Alert/action flagNone / Alert / Action / OOLYesReviewerOn review
Deviation refTextIf flaggedQAOn excursion
SamplerInitialsYesSamplerAt sampling
ReviewedInitials + dateYesReviewerOn review

Blank log

Point / IDDate/timeConductivityTOC (ppb)MicrobialEndotoxinFlagDev refSamplerReviewed
<<FILL>><<FILL>><<FILL>><<FILL>><<FILL>><<FILL>><<FILL>><<FILL>><<FILL>><<FILL>>
<<FILL>><<FILL>><<FILL>><<FILL>><<FILL>><<FILL>><<FILL>><<FILL>><<FILL>><<FILL>>

Instructions

  1. Record online conductivity and TOC values at sampling; enter microbial counts when the incubation completes (the row stays open until then).
  2. Flag each result: None (below alert), Alert (at/above alert, below action), Action (at/above action), or OOL (chemical out of compendial limit).
  3. Any Alert flag prompts a trend look; any Action or OOL flag prompts a deviation and product-impact assessment per the monitoring SOP, and the deviation reference is entered.
  4. A reviewer signs each row; trends are reviewed on the defined cadence, not only per sample.
  5. Retain for not less than <<FILL: retention period>>.

References

USP <645> Water Conductivity; <643> Total Organic Carbon; <85> Bacterial Endotoxins Test; USP <1231>; the PW and WFI monographs. European Pharmacopoeia PW and WFI monographs.

Confirm the current version of each chapter before issue.


Filled specimen

Illustrative rows for a WFI loop, alert microbial 3 CFU/100 mL, action 10, TOC action 500 ppb.

Point / IDDate/timeConductivityTOC (ppb)MicrobialEndotoxinFlagDev refSamplerReviewed
POU-032026-06-08 07:351.0 uS/cm at 20 C1100 CFU/100 mL<0.005 EU/mLNone-J.K.R.G. 06-10
POU-072026-06-08 07:401.1 uS/cm at 20 C12014 CFU/100 mL<0.005 EU/mLActionDEV-2026-0163J.K.R.G. 06-10
Tank return2026-06-08 07:451.0 uS/cm at 20 C1151 CFU/100 mL<0.005 EU/mLNone-J.K.R.G. 06-10

The POU-07 row carries an Action flag and a deviation reference: the log shows both that the exceedance was caught and that it was routed, which is what a reviewer and an inspector look for.

Common inspection findings this log prevents

  • Results recorded but never flagged against alert/action, so trends are invisible.
  • An action-level result with no linked deviation, suggesting it was never acted on.
  • Microbial rows closed before incubation completed, understating counts.

How to adapt this log

  1. Set the system, alert, and action levels in the header.
  2. Add columns for any additional attribute you monitor (for example nitrate, ozone residual on an ozonated loop).
  3. Point the deviation column to your real deviation numbering.
  4. Confirm every chapter against the current published version before issue.
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