ISO 17256:2024

Overview

ISO 17256:2024 - Anaesthetic and respiratory equipment - Respiratory therapy tubing and connectors (First edition 2024) defines safety and performance requirements for respiratory tubing, extension tubing and connectors used to convey respirable gases (primarily oxygen, air or breathable medicinal gas mixtures) in healthcare and homecare environments. The standard focuses on secure connections between gas supply devices and patient interfaces, reducing the risk of misconnection and ensuring reliable oxygen delivery outside of anaesthetic machines and ventilators.

Key topics and technical requirements

ISO 17256:2024 builds on ISO 18190 and includes device-specific mandates. Key technical points include:

• Connector design and interchangeability

  • Outlet connector: adoption of the R2 respiratory small-bore connector for patient-end outlets when tubing is not integrated with the patient interface to reduce misconnections.
  • Inlet connector: compatible with the EN 13544-2 style elastomeric (funnel) connector or optional gas-specific threaded inlet connectors.

• Mechanical strength and attachment

  • Tubing and extension tubing must withstand an axial force of (40 ± 1,5) N; connectors shall be permanently attached (not removable without a tool).
  • Integrated tubing must not detach from a patient interface under the same axial force.

• Retention and leakage

  • Elastomeric funnel connectors shall resist detachment at 200 ± 10 kPa when tested on a defined test nipple.
  • Total leakage (including connectors) limited to ≤ 5 ml/min at 600 ± 10 kPa internal pressure.

• Flow performance

  • Resistance to flow must be ≤ 0.9 kPa/m at 4 l/min.
  • Bending test: flow must not reduce by more than 25% when tubing is bent to a semicircle of diameter three times nominal outside diameter.

• Materials and biocompatibility

  • Gas pathway materials require biological assessment per ISO 18562-1; manufacturers must provide documentation demonstrating conformance.

• Test conditions

  • Type tests performed at (23 ± 2) °C and atmospheric pressure; flow/volume rates expressed STPD.

Applications and who uses this standard

ISO 17256:2024 is essential for:

• Manufacturers of respiratory tubing, connectors, nasal cannulae, masks and extension tubing - for product design, testing and regulatory submission.
• Medical device test laboratories - to perform mechanical, leakage and flow tests.
• Clinical engineers and procurement teams - to specify safe, compatible tubing for hospitals, clinics and homecare settings.
• Regulatory bodies and conformity assessors - to verify compliance and reduce misconnection risks in patient gas delivery systems.

Keywords: ISO 17256:2024, respiratory tubing, connectors, respiratory therapy, extension tubing, R2 connector, elastomeric funnel, biocompatibility, oxygen delivery, misconnection prevention.

Related standards

• ISO 18190 - General requirements for airways and related equipment
• ISO 18562-1 - Biocompatibility evaluation of breathing gas pathways
• ISO 80369-2 - Respiratory small-bore connectors
• ISO 5367 - Breathing tubes for breathing systems (excluded from ISO 17256 scope)
• ISO 4135, ISO 20417, ISO 21920-1 (referenced for terminology, labeling and surface texture)