Do napkin math on how much lead is actually in a 3d print. Then think about the exposure that actually translates to, since most of that is buried inside a print.
We're talking micrograms per kg with a brass nozzle, unless you're printing in an abrasive filament. Possibly less - nozzle wear with non-abrasive filaments is very minor. If you're using a steel nozzle... Well, besides the fact that your steel nozzle probably doesn't contain lead, you're looking at an order of magnitude less wear or better.
I've heard of 3D prints being not-food-safe for a host of reasons, but lead is a new one. How does lead get into the filament? Care to share an article?
Mostly from some nozzles with leaded brass components, but lead is probably very small component and I'm not sure is the main reason why something printed isn't food safe. Mostly I think it's not food safe because it's not really a traceable chain, has very high surface areas, lots of bacterial pockets, generally hard to determine if it's food safe or not.
But wrt to lead, it would mostly be in brass components
Out of the random materials like ground seashells or exotic metals like tungsten I don't think anyone has ever made a lead-fill composite filament. And that is what I call a missed opportunity
