It's so stable you can set it on fire and even stomp on it, you shouldn't but it's unlikely to go off if you did. The only thing that can really set it off is a blasting cap or other form of explosive.
I always thought it was triggered by electricity too because of the wires going to it. Turns out those are just connected to a small electrically triggered secondary explosive in the C4 that sets of the C4 reaction when it explodes.
It's fine as long as you wash it down with nitroglycerin.
At room temp it's so unstable you can set it of with a hammer and the sensitivity goes up with temperature.
One of my family members is a veteran and apparently it wasn’t rare for people in the military to eat C4. They knew a dude who ate some and had a seizure because of it.