Buyers must distinguish between USP/BP/EP/FCC grades depending on the application. For the food industry, purity levels of ≥99% are standard. For pharmaceutical or supplement use, pay attention to the mesh size (fine powder vs. granular); granular forms are preferred for direct compression tableting to ensure flowability, while fine powder is better for instant drinks or topical serums. Additionally, verify the heavy metal content (Lead <2ppm, Arsenic <1ppm) to meet international safety thresholds.