Limestone Flux & Other Calcareous Stone for Lime or Cement Manufacture

The classification of limestone under 2521000000 is specifically for material used or intended for use in the manufacture of lime or cement, or as a metallurgical flux. Crushed limestone used as road aggregate or fill material is classified under heading 2517. The declared end use and the physical and chemical specifications of the material — particularly CaCO₃ purity and particle size — are the key factors customs authorities examine to determine the correct heading.

Both Jamaica and the Dominican Republic have large, high-purity limestone deposits that are geologically well-suited for flux and cement applications. Their island locations enable cost-effective bulk vessel loading directly to US Gulf and East Coast ports, often at lower freight costs than overland shipment from inland North American quarries. This maritime logistics advantage makes them competitive despite the absence of a land border with the US.