Overview
Helium is used in respiratory applications, imaging, and analytical calibration. While not always included as a full EP monograph, it must meet general standards for medicinal gases, including inertness and low impurity levels.
EP Monograph Considerations
- Purity: Typically >99.5%
- Impurities: Oxygen, moisture, hydrocarbons, reactive gases
- Tests: Identity via thermal conductivity detection or mass spectrometry; trace impurities via GC or IR.
Testing Techniques
- Thermal conductivity detectors (TCD)
- Electrolytic hygrometer (moisture)
- IR analysis (hydrocarbons)
- Gas chromatography (full impurity profile)
Applications
- Respiratory therapy in asthma and COPD
- MRI quenching and calibration
- Leak detection
- Inerting of sensitive systems
