You need about 5% of oxygen in your hydrogen to make it explosive, and the bell is getting emptied repeatedly. The guy already shows that the oxygen concentration is low enough to not cause a bang.

NileRed. How to make an Oxygen Generator (MnO2_H2O2 Method) Posted: October 8, 2024 | Last updated: October 8, 2024. More for You ...

Major commercial ozone generator market participants include BIO-UV, DEL Ozone, Eltech Ozone, Faraday Ozone, Lenntech Water Treatment, ORAIPL, Oxidation Technologies, Oxyzone International, Ozone ...

On most commercial airlines, the pressurized cabin will have effectively the same oxygen concentration that would be experienced at an elevation of 5,000-6,000 feet when flying at 35,000 feet.

Three engines are being marketed, including the YF-102 kerosene-liquid oxygen gas generator engine, which uses 3D printing techniques and the vacuum-optimized YF-102V.