What filaments are safe for use with food?

3D printing food-related items is not safe.

Although some types of PLA, PET and Nylon filament carry FDA certifications, the printing process generally renders the final result unsafe for food use. These certifications only apply to the raw materials, and not to the final result. FDA-certified filaments include Taulman Nylon 680 and Taulman T-Glase. 

3D printed objects are inherently porous and contain many small crevices in which bacteria can grow, and these bacteria cannot be removed easily through washing. In addition, most printers use brass nozzles which can deposit trace amounts of lead into the filament while printing.