HS code · 6-digit subheading
HS Code 3812.31 – Anti-oxidising preparations and other compound stabilisers; for rubber or plastics, mixtures of oligomers of 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ)
HS code 3812.31 is the 6-digit subheading for anti-oxidising preparations and other compound stabilisers, for rubber or plastics, mixtures of oligomers of 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ). It is used for TMQ antioxidant powder, liquid TMQ blends, rubber anti-aging agents, polymer heat stabilizers and ozone resistance additives.
What HS 3812.31 covers
This specific category covers anti-oxidising preparations and compound stabilisers for rubber or plastics, specifically those based on mixtures of oligomers of 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ). TMQ is a highly effective antioxidant widely used in the rubber industry, particularly for tires, conveyor belts, and other products requiring excellent heat aging and fatigue resistance. These preparations prevent degradation caused by oxygen, heat, and ozone, thereby extending the lifespan and maintaining the performance of rubber and plastic articles. Manufacturers of tires, automotive components, and industrial rubber goods are primary consumers. Importers and exporters are typically specialized chemical companies and distributors. The trade focuses on high-performance applications where durability under harsh conditions is paramount. Understanding the specific oligomeric composition and its impact on processing and end-product properties is key. Regulatory aspects, especially regarding food contact or specific environmental standards, can also influence market demand and trade flows for these specialized stabilizers.
- Covers
- TMQ antioxidant powder
- Liquid TMQ blends
- Rubber anti-aging agents
- Polymer heat stabilizers
- Ozone resistance additives
- Fatigue resistance compounds
- Vulcanization retarders (secondary effect)
- UV light stabilizers (secondary effect)
- Examples
- Naugard Q
- Vulkanox HS
- Antioxidant TMQ
- Wingstay 29
- Lowinox TMMQ
Codes often confused with 3812.31
Common mistake. This code is distinct from 381239 because it specifically covers TMQ oligomers; confusion might arise if other types of anti-oxidants are mistakenly classified here, or if the product is a raw chemical (e.g., 2,2,4-trimethyl-1,2-dihydroquinoline monomer) rather than a prepared mixture.
Top exporters and importers of HS code 381231, 2025
In 2025, the largest exporter of HS code 381231 in UN Comtrade data was Italy, with 38% of world exports; the largest importer in UN Comtrade data was the United States, with 16% of world imports. Countries that did not report 2025 data are estimated from partner records, which can understate them.
Top exporters 2025 · share of world exports
- 1 Italy $125M 38% of world exports
- 2 China $89M 27% of world exports
- 3 Germany $58M 18% of world exports
World total: $333M Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 United States $38M 16% of world imports
- 2 Thailand $23M 9.7% of world imports
- 3 Indonesia $19M 8.3% of world imports
World total: $236M Reported figures on UN Comtrade ↗
How these figures are built
109 countries reported 2025 trade to UN Comtrade in HS 2022, and their own totals are used. Countries that did not report are estimated from what other countries recorded trading with them. Those estimates miss trade with other non-reporting countries, so they can be low, and a non-reporting country can rank higher than shown or be missing from the list. World totals add both and leave out trade between two non-reporting countries. Figures are in current US dollars; reported imports are mostly valued CIF and exports FOB, and exports include re-exports. The UN Comtrade links show the underlying records; they can also list a few reporters left out here (regional groups and older HS editions).
Source: UN Comtrade (United Nations Statistics Division), 2025 annual data.
Brazil NCM code for 3812.31
Brazil does not split HS 3812.31: its NCM code is 3812.31.00.
All Brazil NCM codes in heading 38.12 →
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text is official; the English is our translation.
Questions about HS 3812.31
What is HS code 381231?
HS code 381231 is a 6-digit subheading in the Harmonized System that covers: Anti-oxidising preparations and other compound stabilisers; for rubber or plastics, mixtures of oligomers of 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ). This specific category covers anti-oxidising preparations and compound stabilisers for rubber or plastics, specifically those based on mixtures of oligomers of 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ). TMQ is a highly effective antioxidant widely used in the rubber industry, particularly for tires, conveyor belts, and other products requiring excellent heat aging and fatigue resistance. These preparations prevent degradation caused by oxygen, heat, and ozone, thereby extending the lifespan and maintaining the performance of rubber and plastic articles. Manufacturers of tires, automotive components, and industrial rubber goods are primary consumers. Importers and exporters are typically specialized chemical companies and distributors. The trade focuses on high-performance applications where durability under harsh conditions is paramount. Understanding the specific oligomeric composition and its impact on processing and end-product properties is key. Regulatory aspects, especially regarding food contact or specific environmental standards, can also influence market demand and trade flows for these specialized stabilizers.
What products fall under HS code 381231?
TMQ antioxidant powder, Liquid TMQ blends, Rubber anti-aging agents, Polymer heat stabilizers, Ozone resistance additives, Fatigue resistance compounds, Vulcanization retarders (secondary effect), UV light stabilizers (secondary effect)
What are common misclassifications for HS code 381231?
This code is distinct from 381239 because it specifically covers TMQ oligomers; confusion might arise if other types of anti-oxidants are mistakenly classified here, or if the product is a raw chemical (e.g., 2,2,4-trimethyl-1,2-dihydroquinoline monomer) rather than a prepared mixture.
Which countries are the top exporters of goods under HS code 381231?
In 2025, the top exporters of HS code 381231 in UN Comtrade data were Italy ($125M, 38% of world exports), China ($89M) and Germany ($58M). World exports came to about $333M, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.
Which countries are the top importers of goods under HS code 381231?
In 2025, the top importers of HS code 381231 in UN Comtrade data were the United States ($38M, 16% of world imports), Thailand ($23M) and Indonesia ($19M). World imports came to about $236M, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.
How is HS code 381231 structured?
HS code 381231 is a 6-digit subheading under the Harmonized System. The first 2 digits (38) identify the chapter, digits 3-4 (12) identify the heading, and digits 5-6 (31) specify the subheading. This code is standardized globally by the World Customs Organization.
What is the Brazil NCM code for HS code 381231?
In Brazil, HS code 381231 is NCM 3812.31.00. The last two digits are 00 because Brazil does not split this HS code further.