ISO 5367 Anesthesia and Respiratory Equipment - Respiratory Devices and Fittings

The ISO 5367 “Anesthesia and respiratory equipment – ​​Respiratory devices and fittings” standard, published by the International Organization for Standardization (ISO), describes the minimum requirements for respiratory sets and breathing tubes designed for use with anesthesia respiratory systems, ventilator respiratory systems, humidifiers, or nebulizers. This standard applies to respiratory sets, breathing tubes, and patient end adapters supplied already assembled, as well as those supplied and assembled as components according to the manufacturer's instructions. It also applies to respiratory sets containing special components (e.g., water traps) between the patient end and the device end. Furthermore, it includes provisions for coaxial and related bifurcated, dual-lumen, or multi-lumen respiratory sets and breathing tubes suitable for use with patient end adapters.

For the purposes of this standard, the following definitions apply in addition to the terms and definitions given in ISO 4135:

• Patient end adapter: A tubular connector with multiple connection points. One of these is the patient connection point. Examples of patient end adapters include Y-pieces, swivel adapters, and other specialized adapters for coaxial, multiple tubes, and bifurcated tubes.
• Flat end: The end of a breathing tube designed to fit directly onto a conical connector conforming to the ISO 5356-1 standard.

As general requirements, the “ISO 18190 Anesthesia and respiratory equipment - General requirements for airway devices and related equipment” standard applies. An informative list of identified hazards is included in this standard (Annex B).

Reusable breathing sets and breathing tubes must comply with the requirements of this standard for their recommended service life, as specified in this standard. Compliance should be checked by examining the manufacturer's technical documentation.

Respiratory devices must also be evaluated and tested in accordance with the ISO 18562-1 standard. Conformity should be checked by reviewing the manufacturer's technical documentation.

In short, ISO 5367 is an international standard that regulates the design, performance, and safety requirements of respiratory devices and connectors used in anesthesia and respiratory equipment.

This standard specifies minimum requirements for the following components:

• Respiratory sets (also known as respiratory circuits)
• Breathing tubes
• Connectors and patient end adapters

These components are designed for use with:

• Anesthesia respiratory systems
• Ventilator respiratory systems
• Humidifiers
• Nebulizers

This standard applies to both pre-assembled kits and components assembled according to manufacturer instructions. Special configurations such as coaxial, bifurcated, dual-lumen, or multi-lumen tubes are also included. This standard does not cover related accessories such as exhalation valves, heat and moisture exchangers, breathing filters, or reservoir bags, which are addressed in separate standards such as ISO 5362 and ISO 23328-2.

Breathing circuits are critical for delivering oxygen and anesthetic gases to patients while removing carbon dioxide during surgery or mechanical ventilation. The ISO 5367 standard ensures the following:

• Equipment compatibility (e.g., tapered fittings according to ISO 5356-1 standard)
• Resistance to bending, collapsing, and leakage.
• Biocompatibility and cleanliness
• Suitable flow characteristics and minimum resistance.

Compatibility enhances patient safety, reduces risks such as incorrect connections or airflow obstructions, and supports global interoperability of medical devices.

For manufacturers and healthcare providers, compliance with the ISO 5367 standard is required for regulatory approval in many countries.

Breathing sets, tubes, and connectors used in anesthesia and respiratory systems are critical life-support devices that deliver oxygen and anesthetic gases to patients while removing carbon dioxide during surgery, mechanical ventilation, or intensive care. Non-conformity can lead to very serious consequences, therefore this standard is vital for patient safety, device reliability, and global regulatory compliance. The main reasons why this standard is important are:

• It enhances patient safety by preventing common hazards: Respiratory circuits are prone to malfunctions that can lead to hypoxia, hypercarbia, or barotrauma. This standard mandates certain tests and design features to mitigate these risks:
• Resistance to bending and collapsing: Prevents gas flow obstruction that could lead to hypoxia.
• Leak prevention and secure connections: Reduces the risk of connection breaks or incorrect connections that can prevent patients from being properly ventilated during anesthesia induction.
• Flow resistance and pressure limits: Provides low resistance for efficient ventilation while preventing excessive pressure.
• Biocompatibility and cleanliness: Minimizes infection risks and material-related complications.

Real-world events highlight these dangers. Manufacturing defects, foreign objects, or incorrect connections in breathing circuits have led to ventilation failures, fires in operating rooms, or hypoventilation incidents.

• It ensures interoperability and compatibility: This standard requires connectors to comply with the ISO 5356-1 (conical connectors) standard, preventing dangerous incorrect connections between different medical tubing systems (e.g., mixing up anesthesia lines with IV or enteral feeding tubes). Standardized dimensions promote seamless integration between equipment from different manufacturers worldwide.
• It supports regulatory compliance and market access: Compliance with this standard is often mandatory or harmonized for approvals under frameworks such as the FDA or other global regulations. It facilitates CE marking, FDA approval, and international trade by demonstrating that devices meet essential safety and performance criteria. Non-compliance carries the risk of recalls, legal issues, or market exclusion.
• It supports quality and reliability in intensive care: Typical adaptive breathing circuits used during surgery demonstrate the safe installations provided by the standard.

In short, the ISO 5367 standard directly contributes to reducing preventable adverse events in high-risk environments such as operating rooms and intensive care units, saving lives and aligning with broader medical device safety goals (e.g., the UN sustainable development goal of good health and well-being).

For many years, our organization, with its competent and experienced staff, has been understanding the needs of its customers, providing the advanced testing services they require, and assisting them in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services to businesses in accordance with the "ISO 5367 Anesthesia and respiratory equipment - Respiratory devices and fittings" standard.