ISO 11195:2018

Overview - ISO 11195:2018 (Gas mixers for medical use - Stand‑alone gas mixers)

ISO 11195:2018 specifies performance and safety requirements for stand‑alone gas mixers used to mix oxygen with one other medical gas. The standard addresses risks unique to portable and bench‑mounted mixers - notably the hazard of reverse gas flow that can contaminate supply systems or deliver incorrect gas mixtures. It defines essential performance, safety, marking and documentation requirements, and test methods (see annexes).

Exclusions: ISO 11195:2018 does NOT apply to:

• blocks of flowmeters with separate controls for each gas
• mixers that mix oxygen with ambient air
• mixers with more than two gas inlets
• mixers connected to an oxygen concentrator

Key topics and technical requirements

ISO 11195:2018 covers technical and safety topics including:

• Essential performance requirements and risk management (aligned with ISO 14971)
• Usability and human factors to reduce misuse
• Materials: biocompatibility, phthalates, natural rubber (latex), effects of cleaning/disinfection, gas compatibility, cleanliness and lubricants
• Normal operating conditions and gas supply inlet pressure requirements
• Reverse gas flow prevention and mitigation measures (critical safety focus)
• Leakage to atmosphere limits and test methods
• Alarm systems: electrically and non‑electrically powered alarms; high pressure, differential pressure, and gas supply failure alarm conditions
• Accuracy of indicated oxygen concentration and delivered gas composition
• Gas supply failure behaviors and requirements for oxygen, other medical gases and air/oxygen mixtures
• Connectors and interfaces: inlet and outlet connectors, filters, flow controls, low‑pressure hose assemblies
• Electrical safety, marking, and required accompanying documents (instructions for use, technical descriptions)
• Annex B provides normative test methods for delivered gas, leakage and oxygen alarm duration; Annex A gives rationale.

Applications and practical value

• Ensures the safe design and reliable operation of stand‑alone gas mixers used in clinical settings (e.g., wards, emergency care, transport, therapy devices that require precise oxygen blending).
• Supports manufacturers in meeting medical gas safety and regulatory compliance for product development, testing and documentation.
• Helps hospitals, biomedical engineering teams, and procurement evaluate equipment performance, safety features and compatibility with existing medical gas systems.

Who should use this standard

• Medical device manufacturers and design engineers for gas mixing equipment
• Test laboratories and certification bodies performing compliance testing
• Biomedical engineers, clinical engineers and healthcare safety officers involved in equipment selection, installation and maintenance
• Regulatory and quality teams preparing technical files and risk assessments

Related standards (normative references)

Includes cross‑references to ISO/IEC and EN standards such as:

• ISO 5359, ISO 7396‑1, ISO 9170‑1, ISO 10524‑1, ISO 11114‑3, ISO 14971, ISO 15001
• IEC 60601‑1, IEC 60601‑1‑8, EN 13544‑2

Keywords: ISO 11195:2018, gas mixers for medical use, stand‑alone gas mixers, oxygen mixing, medical gas safety, reverse flow, alarm systems, accuracy of oxygen concentration.