ANSI/AAMI ST 108:2023

Water for the Processing of Medical Devices

Absolute Water has been at the fore front of designing ultra- pure water systems that meet common sense long standing best practices and guidance from the FDA for years!  

Absolute Water Technologies was also the first Ultra-Pure water treatment company to join the committee to draft AAMI/ANSI ST-108    Water for the Processing of Medical Devices and recruited both competitors and suppliers’ leadership from NuStream and AmeriWater to join!

We have installed, designed and or consulted on hundreds of properly designed and compliant critical rinse systems for medical device reprocessing. When it was just AAMI technical information report 34, we were preaching the importance of patient water safety and fighting against surgical site infections SSI’s.

Sick system?

Water systems looked like this when being serviced by some other large nationwide “industry leaders”. All the yellow was biofilm which includes endotoxin (dead bacteria) and live bacteria residing on instruments used for surgery on your loved ones! We are fighting to make sure your family and friends never have to be subjected to unsafe surgery!

Vet The Company You Are Using!

Do not be fooled by “johnny come lately’s” joining the band wagon! 

We built and helped create the awareness to start a bandwagon on the crusade for safer hospitals and safer surgeries.

We were the only company on the Standard committee to vote no! Our vote was not needed but a thorough review was completed, and many key areas were added for your safety!

Why?  It was not ready to send out! 

  • We fought to include minimum water loop design standards
  • Regularly recommend disinfection recommendations
  • Increased standards on where to test to ensure a healthy systematic.


We are still leading!  We were asked to Chair the subcommittee on the follow up to ST-108: AAMI TIR119/Ed.1, Guidance on Healthcare Implementation and Use of AAMI ST108.

What are keys to the Standard?

  • Monthly Bacteria & Endotoxin Testing
  • Monthly Loop Disinfection
  • Recirculating Loop & Flow Requirements
  • Minimum Water Quality Requirements
  • System Validation & Monitoring
Water Quality Measurement Units Utility Water Critical Water Steam*
pH @ 25°C pH 6.5 – 9.5 5.0 – 7.5 5.0 – 9.2**
Total Alkalinity

Mg CaCO3/L

<400 <8 <8
Bacteria CFU/mL <500*** <10 N/A
Endotoxin EU/mL N/A*** <10 N/A
Total Organic Carbon (TOC) Mg/L (ppm) N/A <1.0 N/A
Color and Turbidity Visual

Colorless, clear, without sediment

Colorless, clear, without sediment

Colorless, clear, without sediment

Conductivity us/cm(microsiemens) <500 <10 <10
ST108 Water Quality Standards

How can Absolute Water Technologies help ensure you are ST108 compliant?

Risk Assessments

Remediation services

Equipment Sales & Preventative maintenance

Design support

Validation Services

Navigating required vs recommended actions of ST108

Download the ST-108 White Paper