ISO 18119: periodic inspection of seamless gas cylinders

Scope

ISO 18119 specifies requirements for periodic inspection and testing to verify the integrity of cylinders and tubes to be re-introduced into service for a further period of time. It applies to seamless steel and seamless aluminium-alloy transportable gas cylinders, single or in bundles, for compressed and liquefied gases under pressure, with a water capacity from 0.5 l up to 150 l, and to seamless tubes above 150 l. As far as practical, it also applies to cylinders below 0.5 l.

What it does not cover

• Periodic inspection and maintenance of acetylene cylinders.
• Periodic inspection and testing of composite cylinders. When composite cylinders are specified, WHO's 2024 technical specifications also list ISO 11623.

Edition and status

• ISO 18119:2018 is edition 1, published in May 2018 by ISO/TC 58/SC 4 (55 pages). It was last reviewed and confirmed in 2023, and ISO says this version remains current.
• Two amendments are published: ISO 18119:2018/Amd 1:2021 and ISO 18119:2018/Amd 2:2024.
• ISO lists the 2018 edition at stage 90.92 (to be revised) and expects it to be replaced by ISO/DIS 18119 within the coming months. The draft second edition (54 pages) is in the enquiry phase; on 16 October 2026 it reached stage 40.93, a decision for a new DIS ballot, and on 22 October 2026 ISO still showed it as under development.
• ISO lists ISO 6406:2005 and ISO 10461:2005, both withdrawn, as the standards that preceded ISO 18119:2018.

Where it appears in medical oxygen documents

• WHO's technical specifications for health facility medical oxygen systems (2024) list ISO 18119 among the standards, or equivalents, for all medical oxygen cylinders.
• In the EU, TPED (Directive 2010/35/EU) subjects marked cylinders to periodic inspections under the Annexes to Directive 2008/68/EC, and the periodic inspection date is marked with the number of the notified body responsible for it (Article 15(7)).
• In UNDP procurement, REQ-OXY-001 (in force since 1 January 2025) still lists ISO 10461 for aluminium cylinder inspection and testing, a standard that ISO shows as withdrawn and as a predecessor of ISO 18119:2018.
• WHO's Foundations of medical oxygen systems (2023), without citing ISO 18119, states that the entity responsible for refilling medical gas must oversee cylinder maintenance every 5 years, with at least a hydrostatic test, a weight loss test (> 5%) and a corrosion test.

Related standards

ISO 18119 deals with cylinders already in service. The requirements at the time of manufacture of refillable seamless steel cylinders are in the ISO 9809 series; ISO 9809-1:2019, for example, specifies minimum requirements for material, design, construction, manufacturing, examination and testing at manufacture.