U.S. imports of Heterocyclic Compounds with Quinoline or Isoquinoline Ring System (NESOI) (HS 293349) totaled $8.0M in August 2026, imported from 22 countries.
Importers of Heterocyclic Compounds with Quinoline or Isoquinoline Ring System (NESOI) paid $664K in duties in August 2026, an average duty rate of 8.36% — duty actually collected as a share of the imports that cleared customs, not the published tariff schedule. Heterocyclic Compounds with Quinoline or Isoquinoline Ring System (NESOI) imports of $8.0M in August 2026 ran 15% below the year-to-date monthly average of $9.3M.
Last updated: August 2026 dataQuinoline and isoquinoline ring-system compounds serve critical roles in antimalarial drug synthesis, veterinary medicine (ethoxyquin as a feed antioxidant, decoquinate as a coccidiostat), and fluoroquinolone antibiotic production. The US schedule provides twelve 10-digit lines under this heading, distinguishing ethoxyquin (2933491000 and 2933491350), drug-containing lines (2933492250 and 2933492600), pesticide lines (2933493000), and general compound lines. India leads US supply, with China a close second; South Korea and Japan are also notable sources. Ethoxyquin imports for animal feed use are subject to FDA Center for Veterinary Medicine review, while fluoroquinolone drug intermediates require FDA drug import compliance.
AI-written summary of the official U.S. Census Bureau trade figures on this page — verify before relying on it.
122 import shipments a month
Yes. Ethoxyquin used in animal feed is regulated by FDA's Center for Veterinary Medicine as a feed additive under 21 CFR. Importers must ensure the product conforms to the approved use conditions and concentration limits. Shipments may be detained for FDA examination if labeling or documentation does not clearly establish the intended use and compliance with applicable feed additive regulations. Consult a licensed customs broker or regulatory counsel familiar with FDA CVM requirements before importing.
4,7-Dichloroquinoline is a specific chemical intermediate — most notably a precursor in chloroquine synthesis — and has its own dedicated line (2933490800) because it is a defined compound rather than a finished drug. Finished pharmaceutical products containing a quinoline ring system classify under the drug-specific lines (2933492250 or 2933492600). The key distinction is whether the imported material is a defined chemical intermediate or a recognized pharmaceutical active ingredient or finished dosage form.
Subheading 8 of 27 in heading 2933
Subheading 293349 · $8.0M of $493.3M
ImportsExports
Imports
$8.0MYoY · free account
Exports
$3.8MYoY · free account
12-mo low · imports
Low · free accountOver the twelve months to August 2026, the U.S. imported $94.7M of Heterocyclic Compounds with Quinoline or Isoquinoline Ring System (NESOI) and exported $15.7M.
Through August 2026. Source: U.S. Census Bureau.
Trade Directory
List your company under HS 293349 — Heterocyclic Compounds with Quinoline or Isoquinoline Ring System (NESOI), so the companies trading it can find you. Be the first supplier listed.
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 |
|---|---|---|---|---|---|
| 2933493000 | Pesticides Cont A Quinoline or Isoquin Ring-Sy Etc | $2.9M | 15.38% | 100.00% | $448K |
| 2933492600 | Drugs Cont A Quinoline or Isoquinoline Etc, NESOI | $2.9M | 0.79% | 12.14% | $23K |
| 2933496000 | Prod in U.S. Note 3 Sec 6 Cont A Quinoline Etc | $1.1M | 9.75% | 81.92% | $109K |
| 2933497000 | Compounds Cont A Quinoline or Isoquinoline Rng Etc | $1.0M | 8.08% | 97.16% | $83K |
| 2933491000 | Ethoxyquin | $36K | 6.50% | 100.00% | $2K |
| 2933492000 | Iodochlorhydroxyquin; Decoquinate Etc | — | -- | -- | -- |
| 2933491500 | 18-Met Hy Lquinoline and Isoquinoline | — | -- | -- | -- |
| 2933491700 | Ethyl-Ethyl-6,7,8-Trifluoro-1,4-Dihydro-4-Oxo- | — | -- | -- | -- |
| 2933490800 | 4,7-Dichloroquinoline | — | -- | -- | -- |
HS10 export codes under this HS6 parent, each with its own page. Source: U.S. Schedule B export classification.
| Code | Description | Export Value |
|---|---|---|
| 2933492250 | Drugs Cont A Quinoline or Isoquinoline Rng-Sys Etc | $2.9M |
| 2933497050 | Cmpds Contain Quinoline/Isoquinoline Ring, NESOI | $978K |
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.
Imports · August 2026
origin
China and Ireland together supply 62% of it. China pays 14.0% duty; India 1.2%.
customs district
destination
entry
rate provision · imports
34.2% enters free of duty; duty collected equals 8.36% of imports for consumption.