# United States tariff line 3812.31.00.00: Mixtures of oligomers of 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ)

> In the United States tariff, line 3812.31.00.00 covers anti-oxidizing preparations and other compound stabilizers for rubber or plastics, mixtures of oligomers of 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ). The general (MFN) duty rate is 6.5%. It falls under HS subheading 3812.31 in heading 38.12 (chapter 38).

Source: https://border.bot/countries/united-states/hs-codes/3812310000
Last updated: 9 October 2026

[Countries](https://border.bot/countries) / [United States](https://border.bot/countries/united-states) / [Chapter 38](https://border.bot/countries/united-states/hs-codes/38) / [3812.31](https://border.bot/countries/united-states/hs-codes/381231) / [3812.31.00.00](https://border.bot/countries/united-states/hs-codes/3812310000)

## Key facts

- Tariff line: 3812.31.00.00
- Covers: Anti-oxidizing preparations and other compound stabilizers for rubber or plastics, mixtures of oligomers of 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ)
- Duty (MFN): 6.5%
- Preferential rates: From free (17 programmes or origins)
- Additional duties: None recorded
- Restrictions: None recorded
- Tariff: [United States](https://border.bot/countries/united-states)
- HS subheading: [3812.31](https://border.bot/hs-codes/381231)

## What this line covers

In the United States tariff, line 3812.31.00.00 covers anti-oxidizing preparations and other compound stabilizers for rubber or plastics, mixtures of oligomers of 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ).

Its legal text is “Mixtures of oligomers of 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ)”, read under “Anti-oxidizing preparations and other compound stabilizers for rubber or plastics”.

## How it is structured

It falls under HS subheading 3812.31 in heading 38.12 (chapter 38). The first six digits are the Harmonized System code; the 4 digits after them are added by the United States tariff.

- Chapter 38: Miscellaneous chemical products
- Heading 38.12: Prepared rubber accelerators; compound plasticizers for rubber or plastics, not elsewhere specified or included; antioxidizing preparations and other compound stabilizers for rubber or plastics
- Subheading 3812.31: Anti-oxidizing preparations and other compound stabilizers for rubber or plastics
- Line 3812.31.00.00: Mixtures of oligomers of 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ)

## Duty

The general (MFN) duty rate is 6.5%.

Duty-free entry applies to goods that qualify under 16 programmes, and to goods from a group of origins (origin group A).

- Free: a group of origins (origin group A) (A)
- Free: United States-Australia Free Trade Agreement (AU)
- Free: United States-Bahrain Free Trade Agreement Implementation Act (BH)
- Free: United States-Chile Free Trade Agreement (CL)
- Free: United States-Colombia Trade Promotion Agreement Implementation Act (CO)
- Free: African Growth and Opportunity Act (D)
- Free: Caribbean Basin Economic Recovery Act (E)
- Free: United States-Israel Free Trade Area (IL)
- Free: United States-Jordan Free Trade Area Implementation Act (JO)
- Free: United States-Korea Free Trade Agreement Implementation Act (KR)
- Free: United States-Morocco Free Trade Agreement Implementation Act (MA)
- Free: United States-Oman Free Trade Agreement Implementation Act (OM)
- Free: Dominican Republic-Central America-United States Free Trade Agreement (P)
- Free: United States-Panama Trade Promotion Agreement Implementation Act (PA)
- Free: United States-Peru Trade Promotion Agreement Implementation Act (PE)
- Free: United States-Mexico-Canada Agreement (S)
- Free: United States-Singapore Free Trade Agreement (SG)

## In other countries

No other national tariff on border.bot has live lines under 3812.31 yet.

- [The Harmonized System text for 3812.31](https://border.bot/hs-codes/381231)

- Previous line: [3812.20.50.00](https://border.bot/countries/united-states/hs-codes/3812205000) Other
- Next line: [3812.39.20.00](https://border.bot/countries/united-states/hs-codes/3812392000) Mixtures of N,N'-diaryl-p-phenylenediamines

## Frequently asked questions

### What does tariff line 3812.31.00.00 cover in the United States tariff?

In the United States tariff, line 3812.31.00.00 covers anti-oxidizing preparations and other compound stabilizers for rubber or plastics, mixtures of oligomers of 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ).

### What is the general (MFN) duty on 3812.31.00.00 in the United States?

The general (MFN) duty rate is 6.5%.

### Which preferential rates apply to 3812.31.00.00?

Duty-free entry applies to goods that qualify under 16 programmes: the United States-Australia Free Trade Agreement, the United States-Bahrain Free Trade Agreement Implementation Act, the United States-Chile Free Trade Agreement, the United States-Colombia Trade Promotion Agreement Implementation Act, African Growth and Opportunity Act, Caribbean Basin Economic Recovery Act, the United States-Israel Free Trade Area, the United States-Jordan Free Trade Area Implementation Act, the United States-Korea Free Trade Agreement Implementation Act, the United States-Morocco Free Trade Agreement Implementation Act, the United States-Oman Free Trade Agreement Implementation Act, the Dominican Republic-Central America-United States Free Trade Agreement, the United States-Panama Trade Promotion Agreement Implementation Act, the United States-Peru Trade Promotion Agreement Implementation Act, the United States-Mexico-Canada Agreement and the United States-Singapore Free Trade Agreement, and to goods from a group of origins (origin group A).

## Sources and updates

The tariff lines for the United States come from border.bot release 1 (edition 2026HTSRev21), read from the publisher’s files, and have been live since 9 October 2026.

The duty rates for the United States come from border.bot release 1 (edition 2026HTSRev21), read from the publisher’s files, and have been live since 9 October 2026.

The trade programmes for the United States come from border.bot release 1 (edition 2026HTSRev21), read from the publisher’s files, and have been live since 9 October 2026.

This page was last updated on 9 October 2026.

Guidance from published tariff data, not a binding ruling. For a decision customs must follow, apply to the destination’s customs authority for a binding tariff ruling.

Official source files:

- https://hts.usitc.gov/reststop/exportList?from=0000000000&to=9999999999&format=CSV&styles=false

Machine-readable: https://border.bot/countries/united-states/hs-codes/3812310000.json