The medical quality is supposed to be non harmful to people, the over the counter street mix are suppose to have added chemical that stink and taste nasty enough that no one would want to get high on it, maybe you can't get high on that mix
Over exposure to N2O is reckoned to cause nerve damage, how much I don't know
Or killing you. Minor side effect.
I had 3 full 20# bottles in the 80's sitting in the garage. Went to put a couple in cars and they were empty. Nobody fessed up, but I knew who the culprit was. Valves were fine.
Don't take that Hair Dryer in the shower with you. Warning labels. oof