Yes — phosphoric acid imported for use as a direct food additive or food-contact substance falls under FDA jurisdiction. Importers must file Prior Notice with FDA and ensure the product meets food-grade purity specifications. Industrial-grade phosphoric acid used solely for non-food applications requires TSCA certification instead.

Diphosphorus pentoxide (P₂O₅) is the anhydrous oxide of phosphorus and classifies under 280910, while phosphoric acid (H₃PO₄) and its condensed forms (polyphosphoric acids) fall under 280920. The key distinction is whether the product is the anhydrous oxide or an acid form; both headings sit within 2809 but carry separate subheading codes.