China accounts for the overwhelming majority of global bulk ascorbic acid production, and imports from China are subject to Section 301 tariffs. Importers sourcing from other origins should maintain robust documentation of manufacturing origin — not just the country of export — to substantiate origin claims and avoid misclassification.

Yes — both enter under 2936270000. However, the FDA regulatory pathway differs: food-additive use requires compliance with GRAS or food additive regulations, while dietary supplement use triggers supplement cGMP requirements. Importers should ensure labeling and documentation reflect the correct intended use before entry.