Canada supplies 46.3% of U.S. imports of Buta-1,3-Diene and Isoprene, across 10 countries (year to date through September 2026).
HHI 2,931 of 10,000 · HHI above 1,800. The sum of each country’s squared percentage share; one country with everything scores 10,000.
10 countries supplying this product to the U.S.
| Rank# | Country | Value | Share | YoY | Duty |
|---|---|---|---|---|---|
| 1 | Canada | $7.6M | 51.7% | +46.2% | 0.0% |
| 2 | Netherlands | $6.3M | 42.5% | -27.6% | 0.0% |
| 3 | China | $848K | 5.8% | -90.6% | 37.5% |
| 4 | Switzerland | $5K | <0.1% | +85.9% | 12.5% |
| 5 | Singapore | -- | 0.0% | -9.5% | -- |
| 6 | Brazil | -- | 0.0% | -60.6% | -- |
| 7 | South Korea | -- | 0.0% | -7.8% | -- |
| 8 | Taiwan | -- | 0.0% | -35.6% | -- |
| 9 | Japan | -- | 0.0% | +21.6% | -- |
| 10 | Kenya | -- | 0.0% | -- | -- |
Duty is the duty Census calculated on this month's imports for consumption from each country, as a share of their customs value. It applies the rates in force, additional duties such as Section 301, 232 and IEEPA included and claimed trade-agreement preferences netted out, so it is an observed rate rather than a statutory one. It is an estimate, not duty collected: antidumping and countervailing duties, fees and later refunds are not in it. YoY compares year-to-date value with the same months last year.