Analysis
HTS 2901.24.50 covers isoprene: other under heading 2901 (acyclic hydrocarbons).
The normal trade relations rate here is zero, shared by about 26% of the 1050 tariff lines in chapter 29, a useful check when a neighbouring dutiable line is a candidate. Free here means free of the base duty only: origin-specific Chapter 99 duties such as Section 301 can still be owed.
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 lines in the same group are 2901.24.10 (buta-1,3-diene and isoprene: buta-1,3-diene, duty-free) and 2901.24.20 (having a purity of 95 percent or more by weight, duty-free).
Census statistics map these goods to NAICS 325110 (Petrochemical Manufacturing), an industry of 76 US establishments employing 10,888 people. That concordance is how imports of this line are compared with US output.
All 2 neighbouring lines carry the same duty-free rate, so a borderline choice between them changes the statistics reported, not the duty paid.
Neighbouring lines
| Line | Description | General rate |
|---|---|---|
| 2901.24.10 | Buta-1,3-diene and isoprene: buta-1,3-diene | Free |
| 2901.24.20 | Having a purity of 95 percent or more by weight | Free |