Leak Testing Best Practices: Why Technique Matters

Published on:

February 17, 2026

• Expert Q&A

Question:

What are best practices for performing manual leak testing on flexible endoscopes, and why does technique matter?

Answer:

Manual leak testing is a critical step performed before manual cleaning to help identify damage that could allow fluid to enter the endoscope. Detecting leaks early helps protect internal components, supports effective reprocessing, and reduces the risk of device damage.

Effective manual leak testing requires more than simply connecting the leakage tester. Best-practice considerations include:

• Ensure the leak test connector and endoscope connector are dry prior to connection to avoid introducing fluid directly into the endoscope

• In case of a 2-step approach (dry-to-wet), immerse the endoscope only if the dry leak test passed

• Ensure the endoscope is fully pressurized; when performing wet leak testing, this is of particular importance before submersion to avoid potential fluid invasion

• Take sufficient time to inspect the entire endoscope, as leaks can be small and difficult to detect

• Angulate the distal end and manipulate control knobs to place stress on bending sections and seals

• Manual leak testing should be performed in addition to any automated leak testing functions provided by an endoscope washer-disinfector or automated endoscope reprocessor (EWD/AER), in accordance with manufacturer Instructions for Use and applicable guidance

• Know how to proceed if a leak is observed

If bubbles are observed exiting a channel and it is unclear whether they represent a true leak or trapped air, flushing the channel with water (for example, using a syringe) may help remove residual air and allow for clearer observation.

National and regional reprocessing guidelines consistently emphasize performing leak testing in accordance with manufacturer Instructions for Use prior to initiating manual cleaning. Across these frameworks, manual leak testing is recognized as a critical step to help identify damage before fluid exposure, and its effectiveness depends on consistent execution by trained personnel using appropriate technique.

Bottom line:

Manual leak testing is not a checkbox step. Proper pressurization, deliberate inspection, and careful observation help identify damage early and support safe, effective reprocessing.