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?
It's not only the filament, but the extruder.
The CDC has some good info on 3D printers, but they don't mention food safety: https://www.cdc.gov/niosh/publications/numbered/2024-103.htm...
Here is an article on the food side of things: https://spoolhound.com/food-safety-guide
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
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