I'm an amateur at this part, but I've reason to believe it's fine.
The material is a Nylon plastic. "Polyamide PA 2200" according to ShapeWays. This link[1] has details on the material when used with laser sintering and in regard to contact with food. The key quote is "[...]are in compliance with EU Plastics Directive 2002/72/EC for the use with all types of foods except high alcoholic foodstuffs[...]"
That said, there is a porosity issue with 3D printed parts and consequently dry coffee coats the impeller and sticks to the surface right away. It's a big problem if in contact with dairy, meat, liquids, etc. because it harbors bacteria. For this reason, ShapeWays does not claim to be food-grade. I don't think it matters for dry coffee though. Nevertheless, there's a writeup about this on the storefront so customers can make the call if they care about stale coffee on their impeller or not.
[1] https://www.sculpteo.com/static/0.30.0-49/documents/material...
