HTS tariff line · chapter 25
2528.00.00
Natural borates and concentrates thereof (whether or not calcined), but not including borates separated from natural brine; natural boric acid containing not more than 85 percent of H3BO3 calculated on the dry weight
Analysis
HTS 2528.00.00 covers natural borates and concentrates thereof (whether or not calcined), but not including borates separated from natural brine; natural boric acid containing not… under heading 2528 (natural borates and concentrates thereof (whether or not calcined), but not including…). US Customs collects import statistics for it under 3 ten-digit suffixes, reported in kilograms.
There is no general-rate duty on this line, which puts it with roughly 91% of the 78 tariff lines in chapter 25 that are also free. Free here means free of the base duty only: origin-specific Chapter 99 duties such as Section 301 can still be owed.
It is the only US line under subheading 2528.00, so the six-digit code used by every Harmonized System country and the eight-digit US line describe the same goods; a foreign tariff or an exporter's invoice showing 2528.00 points straight here.
Census statistics map these goods to NAICS 21239 (Other Nonmetallic Mineral Mining and Quarrying), an industry of 236 US establishments employing 10,238 people, the industry a domestic producer of these goods reports under.