The demand for ultra-pure hydrogen in fuel cell technologies has necessitated advancements in quality assurance measures. Focus is placed on meeting ISO impurity thresholds through traceable calibration standards and compact analytical instruments. Sensors like OFCEAS, photoacoustic spectroscopy, and mass spectrometry offer high accuracy in detecting impurities. Various sampling protocols, such as gas parallel and serial, are employed at hydrogen refueling stations to minimize contamination risks. Additionally, off-site analysis methods utilizing thermal desorption tubes or liquid sampling enhance accuracy in impurity measurements. The development of reference materials remains a challenge due to the stringent standards required for hydrogen purity. Notwithstanding, efforts to create certified reference materials (CRMs) are ongoing to ensure calibration accuracy and inter-laboratory comparability. Addressing these advancements is crucial for the safe and effective scaling of hydrogen infrastructure globally.