If it strips paint off knives, it ain't really safe. Ecofriendly, Green or not, if it loosens up Epoxy paint, the stuff has hazards. Gloves, eye protection, and a mask if not used in a well ventilated area, read outside, take every precaution possible with your son. A tyvek suit is like 3 bucks at lowes as well, I would say go that way also. I hate to sound like a wuss about this, but I am a father of 2 and I do stupid stuff all the time, but I make my kids walk the straight and narrow when it comes to repeating the things I do. Mostly, because I have made mistakes before and I know the skillet is hot, but my kids haven't learned yet, all the mistakes I've made to so, they get the "treatment".
I'm sure you trust your son, but one splatter of that in the eye, and you might become the father of One Eyed Jack. I don't take those chances.
Moose