Commercial invoices and certificates of analysis should identify the specific grain (e.g., rye, oat, rice, sorghum), the milling method, moisture content, and protein percentage. This documentation supports accurate HTS classification at the 10-digit level — where individual grain flours often have dedicated subheadings — and facilitates FDA admissibility review.

Yes — FDA's gluten-free labeling rule (21 CFR Part 101) sets a threshold of less than 20 parts per million of gluten for products bearing a gluten-free claim. Importers of rice, sorghum, or other inherently gluten-free grain flours must ensure that cross-contamination controls in the foreign facility meet this standard and that labeling complies with FDA requirements before US distribution.