Cleaning Validation. Rinse Water Test Method.

Information & Training. | Product & Process Validation.

Per the FDA CFR’s “Guide to Inspections Validation of Cleaning Processes”, “two advantages of using rinse samples are that a larger surface area may be sampled, and inaccessible systems or ones that cannot be routinely disassembled can be sampled and evaluated.” The rinse water test methods as widely applied can be based on:


pH analysis,

measures of conductivity,

particle counts,

microbial counts,

Total Organic Carbon (TOC) determination,



limulus amebocyte lysate for pyrogens,


Rinse Water Test

Cleaning Validation. Information and Training presentation. >>>

Deficiencies with the rinse water method can relate to uncertainty in the recovery factor, also there can be a dilution of any contamination present of surfaces.

Other sampling methods:

Swabbing involves using a wipe or swab that is moistened with high purity water (WFI – water for injection) that is typically wiped over a defined area in a systematic multi-pass way always going from clean to dirty areas to avoid recontamination – i.e. 10 side by side strokes vertically, 10 horizontally and 10 each with the flip side of the swab in each diagonal direction. For TOC analysis very clean low background swabs or wipes and sample vials such should be used.

Coupon sampling involves the use of a coupons or an actual removable piece of pipe that is dipped into high purity water to extract residues for analysis.

Placebo testing involves using placebo product and analyzing for residues from the previous batch.
Product and Process Validation Full Details

Information & Training.

Product and Process Validation.

  • The Validation Master Plan. Performing a Gap Analysis. Validation in the Design Process. Etc..
  • How to ensure Validation efforts are aligned with potential Risks.
  • How to ensure that Validation activity is appropriately documented, reviewed and aligned with requirements.
  • Information & Training presentation   >>>