HS code · 4-digit heading
HS Code 39.03 – Polymers of styrene, in primary forms
What HS 39.03 covers
Heading 3903 encompasses "Polymers of styrene, in primary forms," representing a vital category of raw material plastics in international trade. This includes general-purpose polystyrene (GPPS), high-impact polystyrene (HIPS), expandable polystyrene (EPS), and significant copolymers such as acrylonitrile-butadiene-styrene (ABS) and styrene-acrylonitrile (SAN). The crucial aspect for classification here is that these polymers must be in "primary forms" – meaning liquids, pastes, blocks, lumps, powders, granules, flakes, or similar bulk materials, not yet processed into semi-finished articles like sheets, films, or tubes. This distinction is critical for trade compliance, as semi-finished or finished products fall under different headings (e.g., 3920-3926), affecting tariffs and regulatory requirements. Polymers of styrene are highly versatile, finding extensive applications in packaging, consumer electronics, automotive parts, and construction. Their trade significance has grown with the expansion of global manufacturing, making them essential inputs for numerous industries. This heading is a cornerstone of Chapter 39, "Plastics and articles thereof," providing the foundational materials for a vast array of plastic products. Accurate classification under 3903 ensures smooth customs clearance, correct duty application, and compliance with international trade regulations, preventing costly delays and penalties.
- Covers
- General-purpose polystyrene (GPPS) pellets
- High-impact polystyrene (HIPS) granules
- Expandable polystyrene (EPS) beads
- Acrylonitrile-butadiene-styrene (ABS) resin
- Styrene-acrylonitrile (SAN) copolymer
- Styrene-butadiene copolymer (SBC) in primary forms
- Styrene-isoprene-styrene (SIS) block copolymers (primary)
- Styrene-butadiene-styrene (SBS) block copolymers (primary)
- Methyl methacrylate-acrylonitrile-butadiene-styrene (MABS) resin
- Acrylonitrile-styrene-acrylate (ASA) resin
- Impact-modified polystyrene
- Transparent polystyrene granules
- Flame-retardant polystyrene
- Foamed polystyrene beads (unexpanded)
- Styrene-divinylbenzene copolymers in primary forms
- Hydrogenated styrene block copolymers
- Polystyrene foam (unexpanded)
- Styrene-maleic anhydride copolymers
- Rubber-modified polystyrene
- Polystyrene powder for compounding
- Recycled polystyrene pellets.
- Examples
A major Taiwanese petrochemical company exports large quantities of ABS resin in pellet form to electronics manufacturers in Vietnam, where it's used to mold casings for televisions and computer monitors. Similarly, a Dutch chemical producer ships expandable polystyrene (EPS) beads to insulation panel manufacturers in Germany and Poland, facilitating the production of energy-efficient building materials for the European construction market. In another trade scenario, a US chemical firm supplies general-purpose polystyrene (GPPS) pellets to packaging companies in Brazil, which convert them into disposable food containers and cutlery for the domestic market, often via bulk ocean freight.
Subheadings under 39.03 5
Codes often confused with 39.03
Common mistake. A common misclassification error occurs when traders confuse styrene polymers with other plastic types, particularly if they are modified. For example, ABS resin might be mistakenly classified under 3906 (Acrylic polymers) if the acrylonitrile content is misjudged, or under 3904 (Halogenated olefins) if flame retardants are present. Another frequent mistake is classifying semi-finished products, such as polystyrene sheets or films, under 3903 instead of the appropriate headings like 3920 or 3921. The key distinction lies in the "primary forms" requirement versus articles that have undergone significant shaping. Careful analysis of chemical composition and physical form is essential to avoid incorrect duty rates and compliance issues.
Top exporters and importers of HS code 3903, 2025
In 2025, the largest exporter of HS code 3903 in UN Comtrade data was South Korea, with 18% of world exports; the largest importer in UN Comtrade data was China, with 13% of world imports. Taiwan did not report 2025 data, and its estimate from partner records misses its trade with other countries that did not report: in 2024 that was 14% of its exports here ($350M, CEPII BACI), so it may rank higher.
Top exporters 2025 · share of world exports
- 1 South Korea $2.9B 18% of world exports
- 2 China $1.8B 11% of world exports
- 3 Taiwan* ~$1.7B 11% of world exports · partner records ↗
Taiwan did not report 2025 data, and its estimate from partner records misses its trade with other countries that did not report: in 2024 that was 14% of its exports here ($350M, CEPII BACI), so it may rank higher.
World total: $16.1B Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 China $2.6B 13% of world imports
- 2 United States $1.2B 6.2% of world imports
- 3 Germany $1.1B 5.9% of world imports
World total: $19.4B 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 marked * did not, so their figures add up what other countries recorded trading with them, and their exports are valued at buyers' CIF prices. 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. UN Comtrade records Taiwan as "Other Asia, not elsewhere specified". Saudi Arabia's exports under that code are left out: they are far too large to be trade with Taiwan, so mostly undisclosed partners. 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.
Questions about HS 39.03
What is HS code 3903?
HS code 3903 is a 4-digit heading in the Harmonized System that covers: Polymers of styrene, in primary forms. Heading 3903 encompasses "Polymers of styrene, in primary forms," representing a vital category of raw material plastics in international trade. This includes general-purpose polystyrene (GPPS), high-impact polystyrene (HIPS), expandable polystyrene (EPS), and significant copolymers such as acrylonitrile-butadiene-styrene (ABS) and styrene-acrylonitrile (SAN). The crucial aspect for classification here is that these polymers must be in "primary forms" – meaning liquids, pastes, blocks, lumps, powders, granules, flakes, or similar bulk materials, not yet processed into semi-finished articles like sheets, films, or tubes. This distinction is critical for trade compliance, as semi-finished or finished products fall under different headings (e.g., 3920-3926), affecting tariffs and regulatory requirements. Polymers of styrene are highly versatile, finding extensive applications in packaging, consumer electronics, automotive parts, and construction. Their trade significance has grown with the expansion of global manufacturing, making them essential inputs for numerous industries. This heading is a cornerstone of Chapter 39, "Plastics and articles thereof," providing the foundational materials for a vast array of plastic products. Accurate classification under 3903 ensures smooth customs clearance, correct duty application, and compliance with international trade regulations, preventing costly delays and penalties.
What products fall under HS code 3903?
General-purpose polystyrene (GPPS) pellets, high-impact polystyrene (HIPS) granules, expandable polystyrene (EPS) beads, acrylonitrile-butadiene-styrene (ABS) resin, styrene-acrylonitrile (SAN) copolymer, styrene-butadiene copolymer (SBC) in primary forms, styrene-isoprene-styrene (SIS) block copolymers (primary), styrene-butadiene-styrene (SBS) block copolymers (primary), methyl methacrylate-acrylonitrile-butadiene-styrene (MABS) resin, acrylonitrile-styrene-acrylate (ASA) resin, impact-modified polystyrene, transparent polystyrene granules, flame-retardant polystyrene, foamed polystyrene beads (unexpanded), styrene-divinylbenzene copolymers in primary forms, hydrogenated styrene block copolymers, polystyrene foam (unexpanded), styrene-maleic anhydride copolymers, rubber-modified polystyrene, polystyrene powder for compounding, recycled polystyrene pellets.
What are common misclassifications for HS code 3903?
A common misclassification error occurs when traders confuse styrene polymers with other plastic types, particularly if they are modified. For example, ABS resin might be mistakenly classified under 3906 (Acrylic polymers) if the acrylonitrile content is misjudged, or under 3904 (Halogenated olefins) if flame retardants are present. Another frequent mistake is classifying semi-finished products, such as polystyrene sheets or films, under 3903 instead of the appropriate headings like 3920 or 3921. The key distinction lies in the "primary forms" requirement versus articles that have undergone significant shaping. Careful analysis of chemical composition and physical form is essential to avoid incorrect duty rates and compliance issues.
Which countries are the top exporters of goods under HS code 3903?
In 2025, the top exporters of HS code 3903 in UN Comtrade data were South Korea ($2.9B, 18% of world exports), China ($1.8B) and Taiwan (about $1.7B). World exports came to about $16.1B, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Taiwan did not report 2025 data, and its estimate from partner records misses its trade with other countries that did not report: in 2024 that was 14% of its exports here ($350M, CEPII BACI), so it may rank higher.
Which countries are the top importers of goods under HS code 3903?
In 2025, the top importers of HS code 3903 in UN Comtrade data were China ($2.6B, 13% of world imports), the United States ($1.2B) and Germany ($1.1B). World imports came to about $19.4B, 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 3903 structured?
HS code 3903 is a 4-digit heading under Chapter 39 of the Harmonized System. The first 2 digits (39) identify the chapter, and digits 3-4 (03) specify the heading. This code contains multiple 6-digit subheadings for precise product classification.