Such Hydrogen leakage is too small to pose any serious risk in most applications. And if there is a major leak, gasoline is far more likely to pose a problem than Hydrogen. It's actually not that easy to get Hydrogen to burn or explode, gasoline on the other hand is easy, and it burns for much longer
https://www.youtube.com/watch?v=7bFJK5kU_UQ&feature=emb_err_woyt
The real issue with Hydrogen is storage density. There are number of proposed solutions, but we're still waiting for one to take off.
Biting the hand that feeds IT
