(Please click through to Think Geek. They might be having a sale!)
This necklace? Totally safe. Not going to kill anyone. You don't even need to have a piece of tape to put over it just to make sure, because it's so unlikely to kill anyone. Unless like you put it on way too tight or something. And then, really, you're just going to pass out and feel kinda stupid when you come to. And possibly have a cute little Baby Groot shaped indentation in your face...