I'm playing an inventor for the first time and having a blast (literally).
<whistle> "Don't mind me, I'm just going to blow up this small pile of junk in the corner. No harm no foul, right?"
He managed to blow up EVERYTHING on the lot, including his Sloppy Jalopy that was parked in one of the parking spaces. I had no idea that this could even happen!
Inventor dude came through it all singed, but alive. I picked up almost 2100 pieces of scrap from the conflagration and I only hit the large piles!
I guess that's what happens when you give explosives to an Insane sim...
Edited to add: And he wasn't even fined!