Product classification
HS code for Plastic stabilizers: 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 plastic stabilizers under HS 3812.31
Plastic stabilizers, specifically those consisting of mixtures of oligomers of 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ), are classified under HS code 3812.31. Chapter 38 covers miscellaneous chemical products. Heading 3812 includes prepared rubber accelerators, compound plasticizers for rubber or plastics, and anti-oxidizing preparations and other compound stabilizers for rubber or plastics. Subheading 3812.31 is a specific provision for TMQ-based stabilizers. These chemicals are essential in the polymer industry to prevent degradation caused by heat, light, or oxidation during processing or throughout the product's lifespan. Because these are "compound" preparations or specific chemical mixtures intended for a functional use in plastic manufacturing, they are classified here rather than as separate chemically defined compounds in Chapter 29. The classification depends heavily on the chemical composition and the intended use. If the stabilizer is a single chemically defined element or compound, it might be classified in Chapter 28 or 29. However, most commercial stabilizers are mixtures or preparations designed for specific industrial performance, which brings them into Chapter 38. This specific subheading for TMQ was created to provide better statistical tracking for this common antioxidant used in both the rubber and plastics industries. These stabilizers are often traded in powder, flake, or liquid form and are added in small percentages to the base resin.
- Covers
- TMQ oligomer mixtures
- Compound anti-oxidants for PVC
- Heat stabilizers for plastic resins
- UV stabilizer preparations for polymers
- Mixed light stabilizers for plastics
- Antiozonant compounds for rubber and plastic
- Also under 3812.31
- Naugard Q
- Vulkanox HS
- Antioxidant TMQ
- Wingstay 29
- Lowinox TMMQ
Codes often confused with 3812.31
Common mistake. Stabilizers are often misclassified under 2933.39 if the importer believes they are pure heterocyclic compounds. However, if they are prepared mixtures, 3812 is correct. They are also sometimes confused with 3901-3914 (Primary plastics), but these codes are for the resins themselves, not the additives. Another potential error is 3824.99 (Other chemical products), but 3812.31 is more specific for stabilizers.
Top exporters and importers of HS 381231 (the code used for plastic stabilizers), 2025
In 2025, the largest exporter of HS 381231 (the code used for plastic stabilizers) 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 plastic stabilizers.
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 plastic stabilizers
Brazil classifies plastic stabilizers 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 plastic stabilizers
What is the HS code for Plastic stabilizers?
The HS code for Plastic stabilizers 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)). For compound stabilizers and anti-oxidants like TMQ, the specific HS code is 3812.31.
How do I classify Plastic stabilizers for customs?
Plastic stabilizers 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.
Are liquid stabilizers included in this code?
Yes, as long as they are compound preparations intended for use as stabilizers in rubber or plastics, the physical form does not change the heading.
Which countries are the top exporters of plastic stabilizers (HS 381231)?
In 2025, the top exporters of HS 381231 (the code used for plastic stabilizers) 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 plastic stabilizers (HS 381231)?
In 2025, the top importers of HS 381231 (the code used for plastic stabilizers) 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 Plastic stabilizers the same in all countries?
The base HS code 381231 for Plastic stabilizers 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 plastic stabilizers in Brazil?
In Brazil, plastic stabilizers (HS 381231) is classified under NCM 3812.31.00.