ISO 18777-2:2025 PDF

Overview

ISO 18777-2:2025 defines the particular requirements for portable units that are part of transportable liquid oxygen systems for medical use in the home-care environment. These portable units are intended to be carried by patients during daily activities and refilled from a base unit via a transfilling device through a dedicated filling port connector. The standard complements ISO 18777-1, which contains common requirements and base unit particulars.

This part addresses safety, compatibility and usability aspects that ensure reliable oxygen delivery without professional supervision.

Key Topics

• Filling port connector compatibility: Portable units shall be provided with a filling port connector that is compatible with the base unit transfilling device to ensure safe transfer of liquid oxygen without spillage under normal and single-fault conditions. The connector is non-user detachable.
• Maximum mass: When filled to maximum and fitted with any recommended or integral conserving device, the portable unit shall have a mass of less than 4 kg. This requirement supports portability and patient independence.
• Conserving devices: Oxygen-conserving devices used with portable units shall conform to ISO 80601-2-67. Manufacturers must document compliance and intended configurations.
• Mechanical strength and carrying straps: Portable units must maintain performance after a 1 m drop onto a hard surface and carrying straps must withstand twice the filled mass, as verified by the tests in Annex A.
• Position-of-use alarm: Portable units shall include an audible alarm that activates if the unit is placed in a position that risks liquid oxygen spillage. The alarm must stop and restore flow when the unit is returned to the normal position.
• Information and marking: Units must be marked to indicate positions of normal use. Instructions for use shall explain positions, alarm function, warnings about flow or spillage, and specify the filled mass in kilograms.

Applications

• Home oxygen therapy programs where patients require a lightweight, portable reservoir for short outings or mobility within the home.
• Medical device manufacturers designing portable liquid oxygen units to meet regulatory and procurement specifications.
• Clinical teams and home-care providers assessing device suitability for unsupervised patient use.

Benefits include improved patient mobility, standardized transfilling compatibility across manufacturers, and enhanced safety through mechanical testing and alarm systems.

Related Standards

• ISO 18777-1:2026 - Common requirements and particular requirements for base units (referenced throughout ISO 18777-2).
• ISO 80601-2-67 - Requirements for oxygen-conserving equipment (applicable to conserving devices used with portable units).

Manufacturers and procurement teams should consult both parts of ISO 18777 as well as ISO 80601-2-67 to ensure full compliance for design, testing, marking and instructions for portable liquid oxygen units.