Wet vs. Dry Leak Testing

Published on:

October 8, 2025

• Expert Q&A

Question:

What is the difference between wet and dry leak testing?

Answer:

Leak testing is an important step in the reprocessing lifecycle that requires pressurizing an endoscope to check for leaks and breaches along the channels and seals. Leak testing can be performed manually with a hand pump or with an automatic leak tester system in both wet and dry conditions. Always follow the leak tester’s and endoscope’s instructions for use (IFU) when performing this procedure.

Wet leak testing involves the complete submersion of an endoscope in water to identify leaks. To prevent potential endoscope damage from fluid invasion, the endoscope must be pressurized prior to submersion and remain pressurized until it has been removed from the water. When a leak is present, air bubbles will escape from the hole or crack and be visible in the water. Wet leak testing must be performed in clean water alone, as the presence of detergent can create bubbles that mask the leak-related bubbles coming from the endoscope.

Dry leak testing differs by not requiring submersion in water. Dry leak testing works by checking for drops in pressurization over a period of time which could indicate a leak. Sometimes, a dry leak test is performed as the first stage in the leak testing procedure, followed by a wet leak test, e. g., to assist the end-user in identifying the location of the leak.

Understanding both leak testing methods can help facilities determine which approach is best for their overall reprocessing workflow. In any case, if a leak is identified, refer to the IFU or contact the manufacturer for guidance on how to properly reprocess the leaking endoscope prior to repair.