U.S. imports of Mixtures of Oligomers of TMQ (2,2,4-Trimethyl-1,2-Dihydroquinoline) (HS 381231) totaled $4.5M in September 2026, imported from 6 countries.
Importers of Mixtures of Oligomers of TMQ (2,2,4-Trimethyl-1,2-Dihydroquinoline) paid $568K in duties in September 2026, an average duty rate of 12.86% — duty actually collected as a share of the imports that cleared customs, not the published tariff schedule. Mixtures of Oligomers of TMQ (2,2,4-Trimethyl-1,2-Dihydroquinoline) imports of $4.5M in September 2026 ran 39% above the year-to-date monthly average of $3.2M.
Last updated: September 2026 dataTMQ — a quinoline-derived antidegradant widely used to protect natural and synthetic rubber from heat aging and oxidation — is classified under a single 10-digit line (3812310000) within the antidegradant subheading of Chapter 38. Germany and Italy lead US import supply, with China and India also significant sources, reflecting both European specialty chemical production and Asian cost-competitive manufacturing. Imports of TMQ from China are subject to Section 301 tariffs, a factor that has increased attention to European and Indian supply as alternatives for tire and industrial rubber goods producers.
AI-written summary of the official U.S. Census Bureau trade figures on this page — verify before relying on it.
78 import shipments a month
TMQ acts as an antidegradant — specifically an antioxidant — that inhibits the thermal and oxidative degradation of rubber during both processing and service life. It is widely used in tire sidewalls, conveyor belts, and other rubber goods exposed to elevated temperatures. The oligomeric mixture form provides a balance of volatility, solubility, and antidegradant efficiency compared to the pure monomer.
If TMQ oligomers are the primary or essential-character component of the blend, classification under 3812310000 is generally appropriate. However, if the blend contains substantial proportions of other antidegradant types — such as phenylenediamine-based antiozonants — the classification may shift to a different subheading based on the dominant component. A binding ruling from CBP is advisable for complex antidegradant packages where the essential character is not clear-cut.
ImportsExports
Imports
$4.5MYoY · free account
Exports
—YoY · free account
12-mo low · imports
Low · free accountOver the twelve months to September 2026, the U.S. imported $33.0M of Mixtures of Oligomers of TMQ (2,2,4-Trimethyl-1,2-Dihydroquinoline).
Through September 2026 · exports 11 of 12 months reported. Source: U.S. Census Bureau.
Imports · September 2026
origin
Germany and Italy together supply 88% of it. China pays 44.0% duty; Germany 10.0%.
customs district
destination
entry
rate provision · imports
duty collected equals 12.86% of imports for consumption.
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 |
|---|---|---|---|---|---|
| 3812310000 | Compnd Plastzrs for Rub/Plast, Trimethyl/Dihydroqn | $4.5M | 10.99% | 100.00% | $496K |
HS10 export codes under this HS6 parent, each with its own page. Source: U.S. Schedule B export classification.
| Code | Description | Export Value |
|---|---|---|
| 3812310000 | Compnd Plastzrs for Rub/Plast, Trimethyl/Dihydroqn | $468K |
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.
Subheading 3 of 4 in heading 3812
Subheading 381231 · $4.5M of $45.3M
Trade Directory
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