Exactly my point. I cant find a solid answer. It seems they use common sense about plastic cutlery in the scenario that youre stopped, and in your EDC bag, pocket, or take-out food bag there is some sort of flimsy disposable plastic silverware set, but I also see other things that state that carrying something that is designed to be a weapon and is made out of a material designed to avoid detection by replacing use of metal to something else like plastic, ceramic, etc, that might be pushing the boundary.
That being said, a little 3" dagger isnt going to be an immediate fight stopper anyway. Id rather just carry my pepper spray. I dont keep it in a pocket, I keep it attached to my pants, behind my belt. I can wear a tucked in shirt, as I do for my job, get patted down, and it is in no way visible or anything you can feel. Id also imagine there isnt enough metal to trigger a metal detector. If a small belt buckle or cuff link wont trigger the detector, the at most small spring that holds the safety down in my POM spray definitely wont. On top of that, a shot to the face with pepper spray WILL immediately take someone out of the fight. Sure, it wont be lethal like a small dagger can be, but Im not trying to kill someone, I just want an attitude adjuster for the drunk guy at the bar that is determined to pick a fight.