The two most popular plastics for 3D printing—ABS and PLA—are generally considered food safe. However, the typical filament you buy off the shelf isn't purely made of these materials.

If you’ve had the misfortune of leaving your 3D printer filament out ... for us once and for all: a food dehydrator works perfectly for drying all that filament that we left out in the rain!

[Matt Thomas] wanted to answer the question of whether 3D printed structures can be food-safe or even medical-safe ... using the armies of 3D printers we had available, then distributed them ...