So you guys mean if I print my dishes every day and throw them away afterwards everything is fine.
Great.
You can get PLA that’s certified as food safe ( https://filaments.ca/products/true-food-safe-pla-water-natural-1-75mm , for example), but you’ve still got the geometry issues people have already mentioned to deal with. You have to coat or smoothe the surface to remove the openings between layers, or disinfect somehow between uses—a nice bleach soak ought to neuter the guck in the interlayer gaps. Above all, use common sense.
No, no no no!
The biggest reason why PLA is generally NOT food safe is not the micro pores that enable bacteria growth, the problem is compounds on the additives used to tint PLA.
There the PLA resin but then there’s whatever random chemical to achieve colour that might NOT be food safe. It could contain traces of Lead or other heavy metals, cancer causing substances and other stuff that is not supposed to be eaten or come into contact with food
There are some that are OK https://all3dp.com/2/food-safe-filament-brands-compared/
Not really. Truly no printed plastic is food safe due to the pores created during the printing process. These pores can house hard to clean bacteria.
There are coatings you can use to eliminate pores that are food safe. But I’m not familiar with them so I couldn’t really point you in the right direction sorry.
It is possible to smooth PLA using ethyl acetate, but I don’t know if that’s good enough for food safety, plus you have to remove the ethyl acetate itself.
PLA won’t survive in a dishwasher. PETG might, but there are no reasonable solvents for smoothing PETG.
Maybe it’d be best to print a mold in PLA, smooth with ethyl acetate, clean thoroughly, and then pour silicone into the mold.