Can you get into more of what migation/food grade specs mean?........
Just ask them for a specification sheet and ask them for a copy of their most recent 3rd party or GFSI (SQF, BRC, IFS, etc.) audit and/or certificate.
If they are local you might want to ask for a look behind the doors.
Most companies do checks on their packaging on a random sampling basis to ensure cleaniness of supply, no particles present, etc.
I think you shoud be good to go with what you have.
The superfood powders, seeds, smoothie mixes etc are pretty much all in the same arena of packaging type.
All the Best,
All Rights Reserved,
Without Prejudice,
Glenn Oster.
Glenn Oster Consulting, LLC
Consultants for SQF, ISO-certified payment systems, Non-GMO, BRC, IFS, Lodging, F&B
http://www.GlennOster.com -- 774.563.6161