U.S. imports of Buta-1,3-Diene and Isoprene (HS 290124) totaled $24.1M in August 2026, imported from 10 countries.
Importers of Buta-1,3-Diene and Isoprene paid $1.9M in duties in August 2026, an average duty rate of 8.01% — duty actually collected as a share of the imports that cleared customs, not the published tariff schedule. Buta-1,3-Diene and Isoprene imports of $24.1M in August 2026 ran 19% above the year-to-date monthly average of $20.2M.
Last updated: August 2026 dataButa-1,3-diene and isoprene are conjugated diene hydrocarbons that serve as the primary monomers for synthetic rubber — including styrene-butadiene rubber (SBR) and polyisoprene — making them indispensable to the tire and automotive industries. The US HTS schedule distinguishes isoprene by purity threshold: line 2901242000 covers isoprene at 95% or greater purity by weight, while 2901245000 covers lower-purity isoprene, and 2901243000 captures isoprene not otherwise specified. Canada and South Korea are the leading US import sources, with the Netherlands, Taiwan, and Brazil also supplying the market. Correct purity documentation is essential for proper tariff-line classification of isoprene shipments.
AI-written summary of the official U.S. Census Bureau trade figures on this page — verify before relying on it.
139 import shipments a month
The US schedule separates isoprene by purity: 2901242000 applies to isoprene with a purity of 95% or more by weight, 2901245000 to isoprene below that threshold, and 2901243000 to isoprene not elsewhere specified. A certified certificate of analysis (CoA) stating the purity percentage is the key document for determining the correct classification and should accompany every shipment.
Buta-1,3-diene is a byproduct of steam cracking, so its availability is closely tied to ethylene production rates and naphtha cracker utilization. Supply tightness in Canada or South Korea — the leading US sources — can quickly affect downstream synthetic rubber manufacturers. Importers relying on a single origin should monitor cracker turnaround schedules and consider maintaining strategic inventory buffers.
Subheading 3 of 6 in heading 2901
Subheading 290124 · $24.1M of $134.0M
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HS10 import codes under this HS6 parent, each with its own page. Source: U.S. Harmonized Tariff Schedule.
| Code | Description | Imports for consumption | Average duty rate | Dutiable Share | Duty Collected |
|---|---|---|---|---|---|
| 2901242000 | Isoprene Purity of 95% or More by Weight | $11.2M | 17.27% | 100.00% | $1.9M |
| 2901241000 | Buta-1,3-Diene | $10.4M | 0.00% | 0.00% | -- |
| 2901245000 | Isoprene Purity Less Than 95% by Weight | $2.5M | 0.00% | 100.00% | -- |
HS10 export codes under this HS6 parent, each with its own page. Source: U.S. Schedule B export classification.
| Code | Description | Export Value |
|---|---|---|
| 2901241000 | Buta-1,3-Diene and Isomer Thereof, Unsaturated | $12.5M |
| 2901243000 | Isoprene | $661K |
Import lines come from the U.S. Harmonized Tariff Schedule and export lines from Schedule B. The two are numbered by different agencies, so the same 10-digit code can appear in both tables describing a different product.
ImportsExports
Imports
$24.1MYoY · free account
Exports
$13.2MYoY · free account
12-mo low · imports
Low · free accountOver the twelve months to August 2026, the U.S. imported $215.7M of Buta-1,3-Diene and Isoprene and exported $137.2M.
Through August 2026. Source: U.S. Census Bureau.
Imports · August 2026
origin
Canada and South Korea together supply 72% of it. Brazil pays 37.5% duty; Canada 0.0%.
customs district
destination
entry
rate provision · imports
43.1% enters free of duty; duty collected equals 8.01% of imports for consumption.