# Ph. Eur. 3098: Oxygen (98 per cent)

Ph. Eur. 3098, Oxygen (98 per cent), is the European Pharmacopoeia monograph for oxygen produced by two-stage adsorption plants, with a nominal content of 98.0% that can vary between 96% and 100%; it was first published in Supplement 11.5 and is listed by EDQM as in use.

## What the monograph covers

Single-stage adsorption (PSA) plants produce oxygen with a nominal content between 90.0% and 96.0%, the rest argon and nitrogen; that gas is Oxygen (93 per cent), monograph 2455. Two-stage adsorption plants produce oxygen with a nominal content of 98.0%, varying between 96% and 100%, and monograph 3098 sets the European Pharmacopoeia quality for it. The monograph also requires a risk assessment to identify any potential impurities that it does not list.

EDQM opened an extraordinary consultation on 16 April 2020, noting that two-stage PSA plants able to produce oxygen with a nominal content of 98.0% were available. The monograph was later first published in Supplement 11.5.

## Status

On 22 October 2026 the EDQM Knowledge database lists monograph 3098 as in use. The full text, with its tests and limits, is in the subscription edition of the European Pharmacopoeia; the public EDQM pages show its status and history.

## The three European oxygen monographs

| Monograph | Production route | Oxygen content |
|---|---|---|
| 2455 Oxygen (93 per cent) | Single-stage adsorption plant | Nominal 90.0% to 96.0% |
| 3098 Oxygen (98 per cent) | Two-stage adsorption plant | Nominal 98.0%, varying between 96% and 100% |
| 0417 Oxygen | Cryogenic distillation | Minimum 99.5% |

## What it means for a hospital or designer

- Know which grade a plant makes. A single-stage PSA plant produces oxygen 93 under monograph 2455; oxygen 98 needs a two-stage plant and falls under monograph 3098.
- The 96% ceiling often quoted for PSA applies to single-stage plants. A Global Fund briefing note of 3 April 2024 states that PSA purity does not exceed 96%, while Ph. Eur. 3098 and the International Pharmacopoeia cover two-stage plants above that level.
- The [International Pharmacopoeia](https://library.ultracontrolo.com/standards/international-pharmacopoeia-oxygen/) (13th edition, 2025) has a matching quality, Oxygen 98%, with not less than 96.0% O2 from a two-stage adsorption plant.
- Expect to document the risk assessment for impurities not listed in the monograph, which 3098 requires.
- Whether oxygen 98 may be used in a given hospital is decided by national rules; confirm it with the health authority.

## Related standards

- Ph. Eur. 2455: Oxygen (93 per cent).
- [Ph. Eur. 0417](https://library.ultracontrolo.com/standards/ph-eur-0417-oxygen/): Oxygen, minimum 99.5%.
- [USP Oxygen 93 Percent](https://library.ultracontrolo.com/standards/usp-oxygen-93/): the US monograph for 90.0% to 96.0% oxygen.

ULTRAOX SC and ST PSA plants from Ultra Controlo state a purity of 94% (±1%) in their datasheets, which is in the oxygen 93 range, not oxygen 98.

### Is oxygen 98 the same as oxygen 93?

No. Oxygen 93 (Ph. Eur. 2455) comes from single-stage adsorption plants at a nominal 90.0% to 96.0%; oxygen 98 (Ph. Eur. 3098) comes from two-stage plants at a nominal 98.0%.

### Is monograph 3098 in force?

Yes. On 22 October 2026 the EDQM Knowledge database lists it as in use; it was first published in Supplement 11.5.

## Sources

- [EDQM Knowledge database, monograph 3098 Oxygen (98 per cent)](https://extranet.edqm.eu/4DLink1/4DCGI/Web_View/mono/3098)
- [EDQM, history of monograph 3098](https://extranet.edqm.eu/4DLink1/Web_mono_hist?3098)
- [EDQM news: consultation on Oxygen (98 per cent)](https://www.edqm.eu/en/newslist/-/asset_publisher/JaJ4OiL8a8pm/content/id/93758)
- [EDQM, history of monograph 2455](https://extranet.edqm.eu/4DLink1/Web_mono_hist?2455)
- [EDQM, history of monograph 0417](https://extranet.edqm.eu/4DLink1/Web_mono_hist?417)
- [WHO, The International Pharmacopoeia, 13th edition (2025): Medicinal oxygen](https://digicollections.net/phint/202502/index.html#d/b.6.1.226)
- [Global Fund / BHI, Briefing Note: PSA Plant Oxygen Purity (3 April 2024)](https://resources.theglobalfund.org/media/lenpqaoa/cr_c19rm-psa-oxygen-purity_technical-briefing-note_en.pdf)
- [ULTRAOX SC and ULTRAOX ST datasheets, p. 2](https://www.ultracontrolo.com/products/ultraox)

Reviewed: 2026-10-22. Ultra Controlo engineering. https://library.ultracontrolo.com/standards/ph-eur-3098-oxygen-98/