Water quality matters

1. Why Does Water Quality Matter in Surgical Instrument and Flexible Endoscope Reprocessing? 

Water touches medical devices throughout nearly every stage of cleaning and reprocessing, but its impact is often underestimated. Minerals, microorganisms, endotoxins, and chemical contaminants can influence detergent performance, leave deposits, contribute to corrosion, and potentially compromise a properly cleaned device. This segment explores why AAMI ST108 treats water as a critical component of the reprocessing process—and why understanding what is in your water is essential to protecting instruments, processes, and patients. 

2. What Is the Difference Between Utility Water and Critical Water Under AAMI ST108? 

Not all water used in medical device reprocessing needs to meet the same specifications. AAMI ST108 distinguishes between Utility Water and Critical Water based on characteristics such as hardness, conductivity, microbial levels, endotoxin, and dissolved contaminants. Knowing when each type is appropriate is essential for effective cleaning and final rinsing. This segment breaks down the differences between Utility and Critical Water and explains where each belongs in the reprocessing workflow. 

3. How Do Water Hardness, pH, Conductivity, Chlorides, and Other Contaminants Affect Medical Devices? 

Spotting, staining, scale, corrosion, and inconsistent cleaning results may appear to be instrument or equipment problems when the real cause is water quality. Hardness, pH, conductivity, chlorides, silicates, metals, and other contaminants can interact with devices and cleaning chemistry in different ways. This segment examines the water characteristics identified in AAMI ST108 and shows how seemingly small changes in water chemistry can create significant consequences in SPD and endoscopy. 

4. What Water Quality Is Required During Manual and Mechanical Cleaning of Surgical Instruments? 

From the decontamination sink to the ultrasonic cleaner and washer-disinfector, water performs different jobs throughout surgical instrument reprocessing. The water appropriate for initial cleaning may not be appropriate for the final rinse before sterilization. This segment follows surgical instruments through the cleaning process to identify where Utility Water can be used, where Critical Water becomes important, and how AAMI ST108 works alongside manufacturers' IFUs to establish a controlled cleaning process. 

5. What Water Quality Is Required When Cleaning and Reprocessing Flexible Endoscopes? 

Flexible endoscopes present unique water-quality challenges because their long, narrow internal channels can retain moisture and contaminants, and many undergo high-level disinfection rather than terminal sterilization. Water used during cleaning, rinsing, and especially after high-level disinfection must therefore be carefully controlled. This segment examines water quality throughout the flexible-endoscope reprocessing cycle and explains why the final rinse represents one of the most important water-control points in the process. 

6. How Can SPD and Endoscopy Departments Demonstrate Compliance With AAMI ST108? 

Having an RO system or water softener does not automatically demonstrate compliance with AAMI ST108. Facilities need to know whether the water actually meets required specifications where it contacts medical devices. That requires qualification, testing, monitoring, documentation, trending, maintenance, and a defined response when results fall outside acceptable limits. This segment outlines how SPD, endoscopy, infection prevention, facilities, and other stakeholders can build a sustainable water-quality management program that turns ST108 requirements into everyday practice.