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
3 declarable lines
Heading 2528 covers natural borate ores and concentrates, whether or not calcined, and natural boric acid that contains no more than 85% H3BO3 on a dry weight basis. It does not cover borates that have been separated from natural brine or otherwise refined chemically. The heading splits by the metal in the borate: sodium borates, calcium borates, and a residual other line. All three lines carry a general (MFN) duty of Free.
Products in this heading
- Tincal (natural sodium borate ore)
- Borax ore concentrates, including calcined material
- Colemanite (natural calcium borate)
- Priceite and other natural calcium borate ores
- Natural boric acid of 85% or less H3BO3 on dry weight
- Crude borate ore that has been washed and concentrated but not refined
How to choose the right subheading
- Metal present in the borate: sodium versus calcium decides between 2528.00.00.05 and 2528.00.00.10
- Whether the material is a natural ore or concentrate rather than a borate separated from natural brine or chemically refined
- For boric acid, the H3BO3 content on a dry weight basis must be 85% or less
- Whether the ore has been calcined, which stays in 2528 and does not move the goods to another heading
- Residual ores that are neither sodium nor calcium borates go to 2528.00.00.50
Often confused with
- Heading 2840Refined borax (sodium borate) made from brine or chemical processing
Borates separated from natural brine and chemically produced borates leave chapter 25 for heading 2840.
- Heading 2810Refined boric acid of more than 85% H3BO3
Heading 2528 covers only natural boric acid at 85% or less on dry weight.
- Heading 2519Natural magnesium carbonate (magnesite)
A different mineral substance with its own chapter 25 heading.
- Heading 2529Feldspar and fluorspar
Other mineral substances mined alongside borates but classified separately.
Frequently asked questions
What is the HTS code for natural sodium borates?
Natural sodium borates and concentrates thereof, whether or not calcined, are classified under 2528.00.00.05, with a general (MFN) duty of Free.
What is the duty on natural calcium borates?
Natural calcium borates enter under 2528.00.00.10 and the general (MFN) rate is Free.
How do I classify calcined borate ore that is not sodium or calcium borate?
Calcination does not move the goods out of the heading, so such material falls to the residual line 2528.00.00.50, which carries a general (MFN) duty of Free.
Guide written from the official schedule text. Rates quoted are general (MFN) rates; check the line page for trade agreement rates and the classification of your exact product.