Both fall under the same SITC heading, but frac sand is graded primarily by crush resistance (K-value), roundness, and sphericity per API standards, while glass-grade silica requires very high SiO₂ purity (often above 99%) and tight iron-oxide limits. Foundry sand has its own AFS grain-fineness specifications. These distinctions affect pricing and supplier qualification but do not create separate tariff lines at the SITC level.

Silica sand is a bulk mineral commodity not currently subject to major Section 301 or antidumping orders in the US, but trade-remedy landscapes change. Importers sourcing from specific origins should verify current CBP guidance and any applicable country-of-origin requirements, particularly for high-purity or processed grades that may be classified differently.