I've a friend who is expecting. There are several adorable weapon themed rattles on thingiverse. I am, however, concerned about safety associated with such a product in the hands of a baby who will gnaw on it. To me the safety concerns here are much larger than for most food handling applications.
What steps should be taken to ensure such a print is safe for use?
This includes: filament selection, pea material selection, wall thickness, smoothing, construction, etc.
My current thoughts are as follows: "food grade PLA", dried peas, sanding, and single piece construction
Also consider the nozzle on your printer. Most nozzles are made of brass, which is not considered food safe due to the presence of small amounts of lead. Stainless steel nozzles are available which will not perform quite as well as brass but are food safe.