# ISO 18119: periodic inspection of seamless gas cylinders

ISO 18119 is the International Organization for Standardization standard for periodic inspection and testing of seamless steel and seamless aluminium-alloy gas cylinders and tubes; the current edition is ISO 18119:2018 with Amendments 1 (2021) and 2 (2024), and a second edition is at draft (DIS) stage.

## 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- ISO lists ISO 6406:2005 and ISO 10461:2005, both withdrawn, as the standards that preceded ISO 18119:2018.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](https://library.ultracontrolo.com/standards/undp-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](https://library.ultracontrolo.com/standards/iso-9809/) series; ISO 9809-1:2019, for example, specifies minimum requirements for material, design, construction, manufacturing, examination and testing at manufacture.

### Does ISO 18119 cover composite cylinders?

No. ISO states that it does not apply to the periodic inspection and testing of composite cylinders or to acetylene cylinders; WHO's 2024 specifications also list ISO 11623 for composite cylinders.

### Is a new edition of ISO 18119 coming?

Yes. A second edition is under development as ISO/DIS 18119; on 16 October 2026 ISO recorded a decision for a new DIS ballot. ISO still lists ISO 18119:2018, with its two amendments, as the current version.

### Which older standards did ISO 18119 replace?

ISO lists ISO 6406:2005 and ISO 10461:2005, both withdrawn, as the standards that preceded ISO 18119:2018.

## Sources

- [ISO 18119:2018, iso.org](https://www.iso.org/standard/61505.html)
- [ISO/DIS 18119, iso.org](https://www.iso.org/standard/89256.html)
- [WHO, Technical specifications for health facility based medical oxygen systems (31 December 2024), PDF](https://iris.who.int/server/api/core/bitstreams/ff437601-add3-44c8-8149-b85f0cdb2b52/content)
- [WHO, Foundations of medical oxygen systems (17 February 2023), PDF](https://iris.who.int/server/api/core/bitstreams/4ad6f5fd-089e-4142-8439-b64e98d816d8/content)
- [Directive 2010/35/EU on transportable pressure equipment, consolidated text of 30 May 2026 (EU Publications Office, Cellar)](http://publications.europa.eu/resource/celex/02010L0035-20260530)
- [UNDP, REQ-OXY-001 V01, Technical & Regulatory Requirements for Oxygen Plants (effective 1 January 2025)](https://healthimplementation.undp.org/wp-content/uploads/2025/01/REQ-OXY-001-v01-UNDP-TECHNICAL-REGULATORY-REQUIREMENTS-FOR-OXYGEN-PLANTS.pdf)

Reviewed: 2026-10-22. Ultra Controlo engineering. https://library.ultracontrolo.com/standards/iso-18119/