Documentation for Shipment of Samples to Brussels from U.S- Powdered Beverage

Hi everyone! My company produces powered beverages that are served in a capsule, added to a machine that dispenses it into a still or sparkling drink (think soda stream). We are currently working on a pilot test with a company in Europe who wants to conduct research testing with selected participants to sample the machine and drinks. They will be shipping us powder samples they sourced, and we will be putting the powder samples through our machine to send pack for the pilot test- it will be sampled by people in various selected offices, but not to general public. I was hoping to get more insight into documentation we will need from the supplier and company we are working with, as this is a foreign supplier and research based sampling. Would this fall under FSVP ruling? Any assistance would be greatly appreciated!