"...onions are a huge magnet for bacteria, especially uncooked onions.You should never plan to keep a portion of a sliced onion...it's not even safe if you put it in a ziplock bag ...in your refrigerator. It's already contaminated enough just by being cut open and out for a bit, that it can be a danger to you."
You can imagine what he says about the diced onion sitting out at at the hot dog stand.
What the HECK is this? If it's even remotely true, I've been cheating death for over fifty years.
Worse, I will shortly be chopping twenty-five or so pounds of onions to set out for unsuspecting patrons of our Rotary hot dog stand over the Father's Day weekend.
Stop me before I kill again!
On the other hand, it's exactly what I've done for the last fifteen years or so, with no reported fatalities so far.