Anhydrous disodium tetraborate (Na₂B₄O₇, with no water of crystallization) is classified under 284011, while the hydrated forms—including the common decahydrate and pentahydrate—fall under 284019. The water content, confirmed by a certificate of analysis, is the determining factor.

Antidumping and countervailing duty orders are product- and country-specific and change over time. Importers should check the current CBP and Commerce Department order lists for the specific borate compound and country of origin before entry. A licensed customs broker can assist with scope determinations.