" Hydrogen possesses the NFPA 704's highest rating of 4 on the flammability scale because it is flammable when mixed even in small amounts with ordinary air; ignition can occur at a volumetric ratio of hydrogen to air as low as 4% due to the oxygen in the air and the simplicity and chemical properties of the reaction."

it also has an auto-ignition of 570 °C...So i wouldn't risk it!

H2 is a very dangerous substance. H2 is small enough to leak out of almost any vessel and burns with an invisible flame

Dear Abbas Solouki

Thank you so much for your comment.

Regards

Ayesha