The Use of Alcohol Flushing in Endoscope Drying: Is it Still Necessary?

Alcohol may be introduced into endoscope channels during the final stages of reprocessing as a drying aid.

The practice is based on assisting the removal of residual water from internal channels before storage. Where drying capability was limited, this could form part of the established reprocessing process.

The introduction of Controlled Endoscope Storage Cabinets (ESCs), however, means that some facilities now rely on controlled airflow through or around reprocessed endoscopes to achieve and maintain appropriate storage conditions in accordance with EN 16442.

This changes the context in which the routine use of alcohol should be considered.

The Gastroenterological Society of Australia (GESA) Infection Prevention and Control in Endoscopy 2025 Update specifically considers alcohol flushing in the context of endoscope drying.

GESA notes that there are limited published data supporting the use of an alcohol flush before drying when Controlled Endoscope Storage Cabinets are being used. The guidance also identifies concerns regarding alcohol and the potential fixation of residual protein material within endoscope channels.

The significance of this is not that alcohol flushing should automatically be removed from every reprocessing process. Rather, it indicates that its continued use should have a clearly understood purpose and should be considered in the context of the complete validated reprocessing and drying process.

The discussion around alcohol becomes particularly important when considered alongside cleaning efficacy.

Drying occurs after cleaning and disinfection. Effective cleaning should therefore already have removed contamination from the surfaces and internal channels of the endoscope.

The concern identified by GESA is that alcohol may potentially contribute to fixation of residual protein material if that material remains within the endoscope.

Cleaning efficacy and drying performance are separate but connected elements of the reprocessing pathway, and both need to perform effectively.

EN 16442 applies to controlled-environment storage cabinets used for processed thermolabile endoscopes.

Importantly, the Standard is concerned with the performance of the storage cabinet, including its ability to maintain the microbiological quality of processed endoscopes during storage and, where the cabinet incorporates drying functionality, its drying performance.

This shifts the emphasis from assuming that a particular drying technique is required to demonstrate that the drying process achieves its intended outcome.

Where a Controlled Endoscope Storage Cabinet is relied upon to dry internal endoscope channels, the relevant question therefore becomes:

Can the drying process demonstrate that the endoscope channels achieve the required dryness within the established process?

If that outcome can be demonstrated without an additional alcohol phase, the purpose and necessity of retaining that phase should be considered.

During Performance Qualification at one healthcare facility, SVA observed that alcohol was routinely injected into endoscope channels during the final vent phase of automated reprocessing to assist drying.

To assess whether the alcohol phase was necessary to achieve the drying outcome, SVA conducted drying function testing using endoscopes that had been reprocessed without the final alcohol phase.

All internal channels tested were dry after three hours within the Controlled Endoscope Storage Cabinets.

The finding did not establish that alcohol flushing is unnecessary in every facility or for every endoscope reprocessing system.

It demonstrated something more specific and useful: in the process tested, effective internal channel drying could be demonstrated without the alcohol phase.

This provided objective evidence upon which the facility could reconsider whether that additional stage continued to provide a necessary benefit.

Reprocessing processes evolve.

Equipment changes. Storage technology changes. Reprocessing chemistry changes. Manufacturer Instructions for Use change. Guidance and Standards also develop as new evidence becomes available.

A process step that was introduced for a legitimate reason should not necessarily remain indefinitely without considering whether it is still required within the current reprocessing system.

This is particularly relevant when a process has multiple mechanisms intended to achieve the same outcome.

Where a facility has implemented a Controlled Endoscope Storage Cabinet with demonstrated drying capability, it is reasonable to consider whether all historical drying practices are still required within the reprocessing pathway.

That assessment should be evidence-based rather than assumed.

Where a change is proposed to an established reprocessing process, the implications of that change should be evaluated and the revised process appropriately demonstrated before it becomes routine practice.

The question of alcohol flushing also illustrates why individual stages of reprocessing should not be considered in isolation.

For flexible endoscopes, the pathway includes:

Cleaning → High-Level Disinfection → Rinsing → Drying → Controlled Storage

Each stage depends to some extent on the effectiveness of the stages preceding it.

A satisfactory drying result cannot correct ineffective cleaning. Equally, an effective cleaning and disinfection process needs appropriate drying and storage conditions to support the condition of the endoscope before its next use.

The objective is therefore not to preserve a particular technique. It is to demonstrate that the complete reprocessing process achieves the required outcome consistently.

Alcohol flushing should not be treated as inherently necessary simply because it has historically formed part of an endoscope reprocessing process. Nor should it be removed simply because another drying technology is available.

The more useful question is:

What function is the alcohol phase performing in this specific process, and can the required drying outcome be demonstrated without it?

Where Controlled Endoscope Storage Cabinets are used, GESA’s current guidance provides good reason to revisit that question. Performance Qualification provides a practical means of gathering the evidence needed to answer it.

In SVA’s testing, removing the final alcohol phase did not prevent the tested endoscope channels from achieving dryness after three hours in the storage cabinets.

That does not establish a universal rule for endoscope reprocessing. It does however, demonstrate the value of testing established practices against the performance of the system actually being used.

The objective is not to demonstrate that a familiar drying routine has been completed. It is to demonstrate that an appropriately reprocessed endoscope is effectively dried and maintained under suitable conditions until its next use.