I have been near electrolytic oxygen/hydrogen generators, though never responsible for their operation or maintenance. Submarine sailors become inured to lots of the alarms on their ships, like salinity alarms and temperature alarms. But not the oxygen generator alarm or the anti-submarine alarms.
The O2 generator was nicknamed The Bomb for the potentially hazardous effects of 3000 psi gasses and high electrical currents. My particular vessel carried five-thousand chlorate candles. Once a danger tag was violated and they were wetted with seawater and each one had to be rinsed and dried and restowed, it took about a week.