ISO/TS 5111:2022

Overview

ISO/TS 5111:2022 - "Guidance on quality of water for sterilizers, sterilization and washer-disinfectors for health care products" provides practical guidance on the quality of water used throughout processing of medical devices and other health care products. It covers water used directly for cleaning, disinfection, rinsing and sterilization; as feedwater for steam generation; as a service or cooling medium to sterilizers and washer‑disinfectors (WDs); and for associated distribution and storage systems. The document clarifies scope and exclusions (for example, it does not replace sterilization process validation standards or prescribe water treatment system designs or pharmaceutical manufacturing water).

Key topics and technical requirements

ISO/TS 5111:2022 organizes guidance around the following technical areas:

• Water quality for different applications - guidance on supply, final rinse, operational qualification (OQ)/performance qualification (PQ) and product‑contact versus non‑product‑contact uses.
• Water treatment systems - considerations for pretreatment, softening, deionization (DI), reverse osmosis (RO), electrodeionization (EDI), ultrafiltration, distillation and other commonly used technologies.
• Water distribution and storage - design and maintenance of storage vessels, pipework, pumps, and in‑line devices (e.g., UV lamps).
• Monitoring, maintenance and control - sampling techniques, chemical and microbial testing, endotoxin considerations, sampling consistency, and frequency recommendations.
• Investigating out‑of‑specification (OOS) results - root cause evaluation, interpretation of results and corrective actions.
• Cleaning and disinfection of treatment systems - access, methods and scheduled maintenance.

The technical specification also includes informative annexes with treatment method summaries and example water‑quality issues and refers to related standards (e.g., ISO 17664 series for manual cleaning guidance and EN 285 for steam attributes).

Practical applications and users

ISO/TS 5111:2022 is intended for:

• Hospital sterile processing departments and central sterile services (CSSDs)
• Medical device reprocessing teams and infection prevention professionals
• Biomedical/clinical engineers and facilities managers responsible for sterilizer and WD utilities
• Quality assurance, validation and regulatory affairs specialists drafting protocols (OQ/PQ) or water‑quality specifications
• Water treatment suppliers and service technicians advising on design and maintenance

Typical uses include defining water‑quality specifications for equipment qualification, selecting appropriate water treatment and distribution solutions, establishing sampling and monitoring programs, troubleshooting microbial or chemical excursions, and developing maintenance/cleaning regimes.

Related standards

• ISO 17664 (processing & manual cleaning guidance)
• EN 285 (steam quality attributes) - note: ISO/TS 5111 does not replace these standards but is complementary.

Keywords: ISO/TS 5111:2022, water quality, sterilizers, washer‑disinfectors, healthcare products, water treatment systems, sterilization validation, medical device reprocessing.