Yes, hydrogen gas can be very explosive when it is pure H2 gas. However, when hydrogen is dissolved in water, it’s completely safe and not explosive—just like gunpowder isn’t dangerous if it’s soaked in water. Also, in the air, hydrogen only becomes flammable if it reaches a concentration of 4.6% or higher, which doesn’t happen with hydrogen-rich water. So there’s no risk of explosion when using or drinking hydrogen water.