Oxygen 93 Percent

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

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1 DEFINITION

Oxygen 93 Percent is Oxygen produced from air by the molecular sieve process. It contains NLT 90.0% and NMT 96.0% by volume of oxygen (O₂), the remainder consisting mostly of argon and nitrogen.

2 IDENTIFICATION

A. The paramagnetic signal exhibited by the Sample gas in the Assay confirms the presence of oxygen.

B. The Sample gas in the Assay meets the Acceptance criteria.

3 ASSAY

Procedure

The certified standards called for in the following test are listed in Reagents, Indicators, and Solutions.

Zero gas: Nitrogen certified standard

Span gas: 93% Oxygen certified standard

Sample gas: Oxygen 93 Percent under test

Mode: Paramagnetic oxygen measurement (see Medical Gases Assay 〈415〉)

Analysis: Determine the concentration of oxygen in percentage by volume in Oxygen 93 Percent using a suitable paramagnetic analyzer. Acceptance criteria: 90.0%–96.0% oxygen by volume

4 IMPURITIES

Change to read:

See Impurities Testing in Medical Gases (ERR 1-Nov-2020) 〈413〉. The detector tubes called for in the following tests are listed in Reagents, Indicators, and Solutions.

4.1 Carbon Dioxide

Sample: Detector tube manufacturer's recommended volume ±5% of Oxygen 93 Percent

Analysis: Pass the Sample through a carbon dioxide detector tube at the rate specified for the tube by the detector tube manufacturer. Acceptance criteria: NMT 300 ppm

4.2 Carbon Monoxide

Sample: Detector tube manufacturer's recommended volume ±5% of Oxygen 93 Percent

Analysis: Pass the Sample through a carbon monoxide detector tube at the rate specified for the tube by the detector tube manufacturer. Acceptance criteria: NMT 10 ppm

5 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in pressurized containers. Container connections shall be appropriate for Oxygen 93 Percent. Adaptors shall not be used to connect containers to patient use supply system piping or equipment.

Labeling: If Oxygen 93 Percent is piped from a remote location to the patient point of use, label each outlet “Oxygen 93 Percent”.