# Oxygen 99.5 (medical oxygen, Ph. Eur. 0417)

Oxygen 99.5 is medicinal oxygen with at least 99.5% O2, produced by cryogenic distillation of air: it is the oxygen covered by European Pharmacopoeia monograph 0417 and the Oxygen 99.5% quality of The International Pharmacopoeia (13th edition, 2025).

The International Pharmacopoeia defines medicinal oxygen as Oxygen 93%, Oxygen 98% or Oxygen 99.5%; mixtures of these qualities may be used, but the monograph requirements do not apply to any mixture. The US Pharmacopeia monograph Oxygen sets a lower minimum, not less than 99.0%. WHO interim guidance (2020) notes that cryogenically produced liquid oxygen is always generated off site, not at a medical facility, and NHS England's HTM 02-01 (2026) notes that cylinders supplied by a gas supplier will be above 99% concentration.

ISO 7396-1:2016 states that where all sources of a pipeline system deliver oxygen, the concentration will be greater than 99%, while a supply mixing Oxygen 93 and oxygen sources can vary between 90% and above 99%. A single-stage PSA plant makes Oxygen 93 instead: Ph. Eur. monograph 2455 covers oxygen from a single-stage adsorption plant, HTM 02-01 gives PSA concentrations of up to 95%, and ULTRAOX SC and ST plants deliver 94% (±1%). See [Ph. Eur. 0417](https://library.ultracontrolo.com/standards/ph-eur-0417-oxygen/) and Oxygen 93 vs 99.5%.

## Sources

- [EDQM, Oxygen (98 per cent) consultation (2020): monographs 0417 and 2455](https://www.edqm.eu/en/newslist/-/asset_publisher/JaJ4OiL8a8pm/content/id/93758)
- [EDQM, Ph. Eur. monograph history, Oxygen (93 per cent) 2455](https://extranet.edqm.eu/4DLink1/Web_mono_hist?2455)
- [The International Pharmacopoeia, 13th edition (2025), Medicinal oxygen](https://digicollections.net/phint/202502/index.html#d/b.6.1.226)
- [USP-NF, Oxygen](https://doi.usp.org/USPNF/USPNF_M59550_02_01.html)
- [WHO, Oxygen sources and distribution for COVID-19 treatment centres, interim guidance (4 April 2020)](https://iris.who.int/server/api/core/bitstreams/17eea7fd-59d9-4523-86eb-acec74fcfd27/content)
- [NHS England, HTM 02-01 Part A (2026), paragraphs 6.111 and 6.112](https://www.england.nhs.uk/wp-content/uploads/2016/05/health-technical-memorandum-02-01-medical-gas-pipeline-systems-part-a-design-installation-validation-verification-aug-2026.pdf)
- [ISO 7396-1:2016, abstract (iso.org)](https://www.iso.org/standard/60061.html)
- [ULTRAOX SC datasheet, p. 2](https://www.ultracontrolo.com/products/ultraox)
- [ULTRAOX ST datasheet, p. 2](https://www.ultracontrolo.com/products/ultraox-st)

Reviewed: 2026-10-22. Ultra Controlo engineering. https://library.ultracontrolo.com/glossary/oxygen-99-5/