If it didn’t explode WHILE the machine was set at 100%, you are fine.
There are NO after-effects of inhaling more than 4.7% hydrogen in your intake breath because any excess hydrogen is inherently and immediately exhaled.
There is NO toxic limit to the gas, just an EXPLOSIVE limit.
But even a static spark to the OUTSIDE of a hose or jar can ignite the gas inside (due to capacitive reactance).
Explosions are RARE, with thousand of people using the BG machines over a decade now, I’ve only heard of 4 explosions, so rare or not, it CAN HAPPEN.
Luckily all 4 were NOT inhaling more than 4% hydrogen so the explosions were contained in the hoses and jars with no one getting hurt.