ISO 23500-4:2024

Overview

ISO 23500-4:2024 - Preparation and quality management of fluids for haemodialysis and related therapies - Part 4: Concentrates for haemodialysis and related therapies specifies the chemical and microbiological requirements for concentrates supplied for haemodialysis and related therapies. Applicable to both liquid and powder concentrates, this standard also covers additives (spikes) and equipment used to mix acid and bicarbonate powders into concentrates at the user’s facility. ISO 23500-4:2024 is the second edition and updates the 2019 edition with clarifications (including alternative endotoxin testing using rFC) and additional guidance on spikes and containers.

Key topics and technical requirements

• Scope and applicability: Requirements apply to manufacturers of concentrates; certain items are excluded (e.g., concentrates prepared from pre‑packaged salts/water at a dialysis facility, pre‑packaged sterile dialysis fluid, sorbent regeneration systems, and patient treatment equipment covered by IEC 60601-2-16).
• Chemical requirements: Specifications for solute composition and chemical grade for concentrates used to make dialysis fluid.
• Microbiological requirements: Testing and limits for microbial contamination and endotoxin levels; acceptance of alternative endotoxin test methods (rFC).
• Physical state & particulates: Criteria and tests for liquid vs powder concentrates and particulate content.
• Additives (“spikes”): Guidance on formulation, intended use, and labelling when concentrates are supplemented on-site.
• Manufacturing and equipment: Requirements for manufacturing equipment, concentrate generators, bulk-delivery systems and materials compatibility.
• Mixing systems at facilities: Requirements for systems used to mix concentrate and water on-site, including disinfection protection, piping, storage tanks and safety/electrical considerations.
• Testing and labelling: Test methods, fill quantity verification and comprehensive labelling requirements to ensure safe, correct use at the point of proportioning.

Applications and users

ISO 23500-4 is intended for:

• Manufacturers of haemodialysis concentrates (liquid, powder, and additives)
• Quality assurance and regulatory teams responsible for product compliance
• Medical device and equipment designers (concentrate generators, mixers)
• Dialysis centre clinical engineers and procurement staff who evaluate concentrate specifications and labelling
• Regulators and notified bodies assessing product conformity

Practical uses include production quality control, formulation approval, supplier evaluation, product labelling, and safe integration of concentrates into dialysis fluid preparation workflows.

Related standards

• ISO 23500-3 - water quality for dialysis fluid (referenced for final dialysis fluid preparation)
• ISO 23500-5 - dialysis fluid requirements (clinical dialysis fluid)
• IEC 60601-2-16 - standards for equipment used to perform patient treatment

Keywords: ISO 23500-4, haemodialysis concentrates, dialysis fluid, concentrate generators, quality management, microbiological requirements, endotoxin testing, bicarbonate concentrates, concentrate mixing, labelling.