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HTS 2528.00.00Natural 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

What that translates to:Natural borates and concentrates; natural boric acid, max 85% H3BO3

Also written 25280000. Rates as CBP is collecting them today. Updated Oct 1, 2026.

Natural borates and concentrates; natural boric acid, max… (HTS 2528.00.00) from China owe 37.5% in total duties as of Oct 1, 2026: no regular duty plus a 12.5% forced-labor tariff (Section 301) and a 25% China tariff (Section 301).

Total duty rate37.5%That's $3,750 on a $10,000 shipment.
Forced-labor tariffSection 301, since Jul 24, 202612.5%
China tariffSection 301, since May 10, 201925%
Regular dutyBase rate (MFN) in the tariff scheduleFree
Total duty37.5%
Court status: Challenged at the U.S. Court of International Trade in In re Section 301 Forced Labor Cases, Court No. 26-03555-3JP, before a three-judge panel. The plaintiffs, Learning Resources and others, have moved for judgment on the agency record, arguing that the action (91 FR 47318) exceeds USTR's statutory authority, is arbitrary and capricious, and is pretextual; 25 states, plaintiffs in Court No. 26-cv-03467-3JP, support them as amici (brief filed Sep 11, 2026). No ruling as of Oct 1, 2026, so the rate is unchanged.
Sources: USITC Harmonized Tariff Schedule, Revision 20 (2026); USTR, Notice of Actions in Section 301 Investigations (forced labor), 91 FR 47318, Jul 28, 2026; HTS 9903.05.31; USTR, Notice of Modification of Section 301 Action (List 3 raised to 25% from May 10, 2019), 84 FR 20459, May 9, 2019; HTS 9903.88.03.

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Official description

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

Legal text from the Harmonized Tariff Schedule, Revision 20 (2026), chapter 25: Salt; sulfur; earths and stone; plastering materials, lime and cement.

Statistical lines

The 10-digit numbers used on entry paperwork. They share this code's duty rates.

  • 2528.00.0005 (2528000005)Natural sodium borates and concentrates thereof (whether or not calcined) · reported in kg
  • 2528.00.0010 (2528000010)Natural calcium borates · reported in kg
  • 2528.00.0050 (2528000050)Other · reported in kg

What changed for this code

Questions about HTS 2528.00.00

What is the duty rate for HTS 2528.00.00?

The regular (column 1 general) rate printed in the tariff schedule is Free. Goods from China owe 37.5% in total as of Oct 1, 2026, including any additional tariffs. Additional tariffs depend on the country of origin; choose one above to see its full rate.

Is HTS 2528.00.00 subject to Section 301 tariffs?

Yes, for goods from 85 countries and territories as of Oct 1, 2026, including Algeria, Angola, Argentina, Australia, Austria. Choose a country above to see the rate and any exemptions.

Is HTS 2528.00.00 subject to Section 232 tariffs?

No Section 232 tariff applies to HTS 2528.00.00 as of Oct 1, 2026, from any country of origin.

HTSLookup shows the duties CBP collects on this code by country of origin. Antidumping or countervailing duties may also apply to some exporters; they're set per company and aren't shown.