Analysis
HTS 2809.10.00 covers diphosphorus pentaoxide under heading 2809 (diphosphorus pentaoxide; phosphoric acid;polyphosphoric acids, whether or not chemically…).
The normal trade relations rate here is zero, shared by about 29% of the 274 tariff lines in chapter 28, a useful check when a neighbouring dutiable line is a candidate. Chapter 99 measures such as Section 301 or 232 can still apply on top, depending on where the goods come from.
Goods from countries without normal trade relations pay the column 2 rate of 25% instead of nothing, so origin decides between free entry and a 25% duty.
The other line in the same group is 2809.20.00 (phosphoric acid and polyphosphoric acids, duty-free).
Census statistics map these goods to NAICS 325180 (Other Basic Inorganic Chemical Manufacturing), an industry of 705 US establishments employing 41,447 people. That concordance is how imports of this line are compared with US output.
Every edition we compared, from Jan 2023 to Oct 2026 (Rev. 22), shows the same general rate of Free.
Neighbouring lines
| Line | Description | General rate |
|---|---|---|
| 2809.20.00 | Phosphoric acid and polyphosphoric acids | Free |