Product classification
HS code for Antioxidants for rubber: 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).
Classification of antioxidants for rubber under HS 3812.31
HS code 381231 is specifically assigned to anti-oxidising preparations and other compound stabilisers intended for use with rubber or plastics, provided they are mixtures of oligomers of 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ). This precise classification highlights the importance of the chemical identity of the antioxidant. TMQ is a widely recognized polymeric hindered amine antioxidant, valued for its effectiveness in protecting rubber from oxidative degradation caused by heat, oxygen, and fatigue. Its specific chemical structure and function are the defining characteristics that place it under this particular HS code, differentiating it from other antioxidant types.
- Covers
- Polymeric hindered amine antioxidants based on TMQ
- TMQ-based stabilisers for natural rubber
- TMQ-based stabilisers for synthetic rubber (e.g., SBR, BR, NBR)
- Antioxidant masterbatches containing TMQ for rubber compounding
- Preparations primarily composed of TMQ oligomers for rubber and plastic applications
- Also under 3812.31
- Naugard Q
- Vulkanox HS
- Antioxidant TMQ
- Wingstay 29
- Lowinox TMMQ
Codes often confused with 3812.31
Common mistake. The most frequent misclassification occurs with HS code 381239, which covers anti-oxidising preparations and compound stabilisers for rubber or plastics that are *not* mixtures of oligomers of TMQ. The crucial difference lies in the specific chemical composition: 381231 is strictly for TMQ-based products, while 381239 is for all other antioxidant types. Another potential area of confusion is with HS code 381210, which pertains to accelerators for rubber. While both are chemical additives used in rubber processing, their roles are fundamentally different: accelerators facilitate vulcanization, whereas antioxidants prevent material degradation and extend product life.
Top exporters and importers of HS 381231 (the code used for antioxidants for rubber), 2025
In 2025, the largest exporter of HS 381231 (the code used for antioxidants for rubber) 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.
Figures cover everything classified under HS 381231, not only antioxidants for rubber.
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 antioxidants for rubber
Brazil classifies antioxidants for rubber under NCM 3812.31.00: HS 3812.31 with 00 added.
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.
Questions about antioxidants for rubber
What is the HS code for Antioxidants for rubber?
The HS code for Antioxidants for rubber is 381231 (Anti-oxidising preparations and other compound stabilisers; for rubber or plastics, mixtures of oligomers of 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ)). The HS code for antioxidants for rubber, specifically those that are mixtures of oligomers of 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ), is 381231.
How do I classify Antioxidants for rubber for customs?
Antioxidants for rubber is classified under HS code 381231 — Anti-oxidising preparations and other compound stabilisers; for rubber or plastics, mixtures of oligomers of 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ). This is a 6-digit subheading level code.
What is 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ)?
2,2,4-trimethyl-1,2-dihydroquinoline (TMQ) is a prominent polymeric hindered amine antioxidant. It is widely utilized in the rubber and plastics industries to provide excellent protection against oxidative degradation, particularly under high-temperature conditions. TMQ functions by scavenging free radicals, thereby inhibiting the chain reactions that lead to material aging and deterioration.
Which countries are the top exporters of antioxidants for rubber (HS 381231)?
In 2025, the top exporters of HS 381231 (the code used for antioxidants for rubber) 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 antioxidants for rubber (HS 381231)?
In 2025, the top importers of HS 381231 (the code used for antioxidants for rubber) 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.
Is the HS code for Antioxidants for rubber the same in all countries?
The base HS code 381231 for Antioxidants for rubber is internationally standardized for the first 6 digits across 200+ countries. Individual countries may add additional digits for national tariff lines and specific classifications.
What is the NCM code for antioxidants for rubber in Brazil?
In Brazil, antioxidants for rubber (HS 381231) is classified under NCM 3812.31.00.