ANSI/AAMI ST108 Disinfection - Water Quality for Medical Devices

Water Treatment Chemicals and AAMI ST108 Disinfection

In the healthcare industry, ensuring patient safety hinges on meticulous sterilization of reusable medical devices. A critical aspect of this process is water quality. The recently introduced ANSI/AAMI ST108 Disinfection standard sets the benchmark for water used in medical device reprocessing, and water treatment chemicals play a vital role in achieving this standard.

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This standard of AAMI ST108 Disinfection covers the selection and maintenance of effective water quality suitable for processing medical devices. It provides guidelines for selecting the water quality necessary for the processing of categories of medical devices and addresses water treatment equipment, water distribution and storage, quality control procedures for monitoring water quality, strategies for bacterial control, and environmental and personnel considerations.

This standard for AAMI ST108 Disinfection addresses the quality of water provided at the point-of-use for medical device processing, including cleaning, rinsing, disinfection, and sterilization. It categorizes water types based on their characteristics and intended usage.

AAMI ST108: A New Era in Water Quality

Our four pillars for ST108 is

The initial risk assessment, which includes laboratory testing and analysis, along with an evaluation of current systems against the standard;
The addition of equipment such as Nusurg or Central Sterile equipment to get them compliant. This could be adding and electrodionizer, or UV filtration.
The performance qualification, which is a year-long process to collect data through laboratory testing
On-going testing to include Endotoxin and bacteria testing, maintenance on the Central Sterile systems, and consumables to maintain those systems

What is new with AAMI ST108 Disinfection?

AAMI ST108 supersedes its predecessor, AAMI TIR34, establishing stricter and more comprehensive guidelines for water quality in medical device reprocessing. This standard emphasizes a multi-pronged approach, encompassing:

Three Water Categories: ST108 defines three water classifications: utility water (initial source), critical water (extensively treated), and steam (used for sterilization).
Multi-Disciplinary Teams: The standard mandates the creation of dedicated teams responsible for water quality management, ensuring collaboration between personnel handling reprocessing and water treatment systems.
- The membership of the multidisciplinary team should include representatives with demonstrated expertise of the following disciplines, but is not limited to:
  - Senior organizational leadership with authority to make command decisions about water restrictions or other response measures (executive sponsorship)
  - Facilities engineering staff
  - Infection prevention and control (IP) program staff
  - Medical device processing personnel with knowledge of water use within the device processing areas (e.g., Sterile Processing Department)
  - Clinical engineering staff with the ability to address risk management and procurement of equipment for water management
  - Surgical suite/procedure room personnel
  - Water treatment specialist
Rigorous Monitoring: ST108 outlines stricter water quality testing requirements at various points, from the treatment system to departmental points-of-use.

Water Treatment Chemicals and ST108 Compliance

Water treatment chemicals are essential tools for achieving the water quality outlined in AAMI ST108. Here’s how some key chemicals contribute:

Disinfectants: Chemicals like chlorine, chloramines, and ozone effectively eliminate microorganisms in utility water. Selection depends on factors like efficacy against specific pathogens, residual levels, and compatibility with other chemicals.
Deionizers: These systems remove dissolved ionic contaminants like minerals and salts, which can interfere with cleaning and disinfection processes.
Reverse Osmosis (RO): RO membranes act as a barrier, filtering out a wide range of contaminants, including microorganisms, endotoxins (bacterial toxins), and organic matter. RO permeate (treated water) forms the basis for critical water.
Ultrafiltration (UF): UF membranes are another filtration technology, primarily used for removing bacteria, viruses, and other large molecules. They can be used in conjunction with RO for additional purification.
Corrosion Inhibitors: These chemicals prevent pipe corrosion, which can release metal contaminants into the water and compromise its quality.
pH Adjusters: Maintaining optimal water pH is crucial for disinfection efficacy and preventing corrosion. Acids or bases might be used for pH adjustment.

Choosing the Right Chemicals

Selecting the appropriate water treatment chemicals requires careful consideration of various factors:

AAMI ST108 Requirements: The chemicals must ensure water meets the specific quality parameters outlined in the standard for each water category.
Compatibility: Compatibility with existing equipment, other treatment chemicals, and the materials used in medical devices is essential.
Safety: The chemicals should be safe for personnel handling them and for the environment after proper disposal.
Efficacy and Cost-Effectiveness: Finding the right balance between effectiveness against contaminants and overall treatment cost is crucial.

Beyond Chemicals: A Holistic Approach

While water treatment chemicals are vital, a holistic approach is necessary for achieving AAMI ST108 compliance. This includes:

Proper System Maintenance: Regular maintenance of water treatment equipment ensures optimal performance and consistent water quality.
Training and Monitoring: Staff responsible for water treatment and device reprocessing require proper training on AAMI ST108 protocols and effective monitoring procedures.
Documentation: Maintaining detailed records of water quality testing and treatment processes is crucial for ensuring compliance and traceability.

By adhering to AAMI ST108 and using the right water treatment chemicals, healthcare facilities can significantly enhance the safety and efficacy of their medical device reprocessing procedures. This, in turn, minimizes the risk of healthcare-associated infections (HAIs) and promotes better patient outcomes.

Contact ChemREADY today to schedule a consultation. Let us help you navigate AAMI ST108 and ensure the continued safety of your patients.

AAMI for Medical Devices

Medical devices can be placed into one of three categories depending on the potential risk for infection associated with their intended use. The Centers for Disease Control and Prevention (CDC) has described the level of disinfection or sterilization needed after decontamination and before patient use for the three Spaulding categories:

Critical devices are instruments or objects that are introduced directly into the human body, either into or in contact with the bloodstream or into other normally sterile areas of the body, and products with sterile fluid pathways.

Examples include surgical instruments, needles, cardiac catheters, implants, etc.

Semi-critical devices are instruments or objects that contact intact mucosal membranes or non-intact skin of the patient during use but do not usually penetrate the blood barrier or other normally sterile areas of the body.

Examples include noninvasive flexible endoscopes, endotracheal and aspirator tubes, etc

Non-critical devices are instruments or objects that usually contact only the intact skin of the patient.

Examples include include bedpans, reusable anesthesia masks, blood pressure cuffs, etc

AAMI ST108 Sterile Processing

The Association for the Advancement of Medical Instrumentation (AAMI) has established a new standard, ANSI/AAMI ST108:2023, critical for sterile processing departments (SPDs). Replacing the previous AAMI TIR34 guidelines, ST108 emphasizes a stringent approach to water treatment, application, and monitoring for safe and effective reprocessing of medical devices.

AAMI ST108 Testing and Consulting

At ChemREADY, we understand the critical role sterile processing departments (SPDs) play in patient safety. Reprocessing medical devices effectively requires meticulous attention to detail, and water quality is a cornerstone of this process. The new AAMI ST108 standard sets stringent guidelines for water purity to minimize patient risk.

AAMI ST108 Videos

Contaminated water is a hidden threat to patient safety. The new AAMI ST108 standard raises the bar for water quality in medical device reprocessing. But don't worry, we've got you covered!

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AAMI ST108 FAQ: Clean Water for Safe Reprocessing

What is AAMI ST108?

AAMI ST108 is a recently released standard that sets stricter guidelines for water quality used in cleaning reusable medical devices. This ensures patient safety by minimizing the risk of infections from contaminated instruments.

What’s new in ST108?

ST108 goes beyond its predecessor by introducing:

Three water categories: Classifies water based on its treatment level (utility, critical, steam) for specific uses.
Multi-disciplinary teams: Requires collaboration between various departments (engineering, infection control) to manage water quality effectively.
Rigorous monitoring: Demands more frequent testing at various points in the system to guarantee consistent water purity.

What are the water categories?

Utility water: The initial source water, often needing further treatment for reprocessing.
Critical water: Highly treated water with minimal contaminants for final rinsing or steam generation.
Steam: Water vapor used for sterilization processes.

What does the team do?

The multi-disciplinary team brings together experts from different areas (reprocessing, engineering, infection control) to ensure everyone understands water quality requirements and works together for effective water management.

How does ST108 affect reprocessing?

Facilities may need to:

Conduct initial assessments to evaluate current systems.
Invest in additional water treatment equipment (e.g., deionization, UV filtration) to meet stricter standards.
Implement a year-long process to verify equipment performance.
Perform ongoing testing for bacteria and maintain water treatment systems.

Where can I learn more about AAMI ST108?

The Association for the Advancement of Medical Instrumentation (AAMI) offers resources on ST108. Visit their website at https://www.aami.org/.