LLDPE HS Code and Tariff: Classifying Resin Correctly for Import

Imported linear low-density polyethylene in primary granular form is classified within heading 3901 as a polymer of ethylene. The six-digit subheading 3901.40 covers ethylene-alpha-olefin copolymers having a specific gravity below 0.94; this is the subheading occupied by most commercial LLDPE grades because the resin is copolymerized with but-1-ene, hex-1-ene, or oct-1-ene and is routinely certified at a density of 0.916–0.940 g/cm³ under ASTM D4976 cell class or ISO 1872-1 designation. Customs classification of LLDPE is not determined by trade name, pellet geometry, film grade designation, or end-use extrusion equipment; it is determined by the physical and structural criteria embedded in GRI 1 and GRI 6, supported by Chapter 39 notes and the explanatory scope of heading 3901. A resin lot described as LLDPE on the commercial invoice may nevertheless fall outside 3901.40 if the certified specific gravity reaches 0.940 or above, if the comonomer is vinyl acetate rather than an alpha-olefin, or if the product has been converted into film, sheet, fiber, or another fabricated article. Misclassification under 3901.10 or 3901.20 can trigger post-entry customs audits, understated revenue recovery, and reassessment of trade remedy exposure.

Why does subheading 3901.40 control most LLDPE imports instead of 3901.10 or 3901.20?

Subheading 3901.10 covers polyethylene having a specific gravity below 0.94, but it is residual for polyethylene that does not meet the narrower ethylene-alpha-olefin copolymer description. Subheading 3901.20 covers polyethylene having a specific gravity of 0.94 or more, regardless of whether short-chain branches derive from an alpha-olefin; a high-density ethylene-hexene copolymer with certified density 0.952 g/cm³ is not classified under 3901.40 because the specific gravity condition fails. Subheading 3901.40 therefore requires two concurrent findings: the polymer backbone must be an ethylene-alpha-olefin copolymer, and the specific gravity must be below 0.94. A film-grade butene-based LLDPE with density 0.918 g/cm³, melt flow rate 1.0 g/10 min at 190 °C/2.16 kg under ASTM D1238, and a carbon-13 NMR comonomer assignment of 7.5 mole% but-1-ene falls within 3901.40. In contrast, a low-density homopolymer made by high-pressure autoclave polymerization with long-chain branching but density 0.923 g/cm³ is a polyethylene below 0.94 and falls under 3901.10, not 3901.40, because it lacks the alpha-olefin comonomer architecture.

The term “alpha-olefin” is not a marketing descriptor. In subheading 3901.40, it refers to an unsaturated hydrocarbon with a primary double bond, such as propene, but-1-ene, hex-1-ene, or oct-1-ene. Confirmation of comonomer type is normally performed by Fourier transform infrared spectroscopy with attenuated total reflectance in the 700–800 cm⁻¹ region for short-chain branching or by 13C NMR integration under ASTM D5017. Commercial certificates of analysis that list only “comonomer: butene” without a structural test method may be insufficient for a customs audit because they do not distinguish an ethylene-butene copolymer from an ethylene-vinyl acetate copolymer or from a high-pressure LDPE containing only alkyl branch artefacts. Chapter 39 Note 5 defines a copolymer as a polymer in which no single monomer unit contributes 95% or more by weight. For LLDPE grades with very low comonomer levels near the 95% ethylene threshold, classification should be supported by a carbon-13 NMR sequence-distribution report rather than by density alone.

The specific gravity threshold is measured at 23 °C and is not equivalent to bulk density. Pellet bulk density can range from 0.48 g/cm³ to 0.58 g/cm³ depending on pellet shape, conveying equipment, and additive load; this property has no bearing on HS classification. The HS criterion uses polymer matrix specific gravity determined by ASTM D792 displacement or ASTM D1505 density-gradient column. A density-gradient column maintained with isopropanol-water or ethanol-water systems and calibrated glass floats can resolve density at 0.0001 g/cm³; commercial certificates of analysis usually report 0.001 g/cm³. Rounding practices matter at the 0.940 boundary. A resin certified at 0.9398 g/cm³ is below the threshold; a resin certified at 0.9400 g/cm³ is not. When a shipment lot is tested by customs and the result is 0.941 g/cm³, classification under 3901.40 is no longer defensible regardless of the invoice description.

Laboratory instrumentation and specimen conditioning for a defensible six-digit classification

Defensible LLDPE classification evidence should include density, melt flow rate, and comonomer identity. Density is measured by ISO 1183-1 method A displacement or ASTM D1505 density-gradient column; the test report should state conditioning temperature, liquid medium, float calibration, and result to four decimal places when resolving the 0.940 boundary. Melt flow rate is measured at 190 °C with a 2.16 kg load using a melt indexer with a 2.095 mm ± 0.005 mm die according to ISO 1133-1:2022 or ASTM D1238. Melt flow rate does not enter the HS subheading directly but verifies the grade against the commercial invoice and can identify drummed product that has undergone thermal degradation. For comonomer identity, ASTM D5017 carbon-13 NMR provides sequence-distribution and comonomer concentration. An FTIR method such as ASTM D5576 can show short-chain branching but is less reliable for distinguishing butene-based LLDPE from hexene-based LLDPE at high resolution. A differential scanning calorimetry trace under ISO 11357-3 can separate a high-pressure LDPE melting endotherm near 106–112 °C from a hexene-based LLDPE melting endotherm near 119–124 °C; however, DSC alone is not sufficient to establish the alpha-olefin copolymer structure for 3901.40 because some high-density ethylene-alpha-olefin copolymers also melt in that range.

At the national-tariff level, the code may differ from the six-digit HS assignment. The U.S. HTS statistical line for the 3901.40 subheading is 3901.40.0000; other jurisdictions may assign different national suffixes, statistical reporting units, or import licensing flags. The importer must not rely on a supplier’s six-digit HS code printed on a certificate of origin. The destination country’s national tariff schedule, binding tariff information, and customs ruling database control the final entry line. Free trade agreement preference claims also require a separate origin analysis; an HS classification under 3901.40 does not by itself confer eligibility for a reduced preferential duty. For resin manufactured in a free trade agreement partner from ethylene and alpha-olefin feedstocks imported from non-party suppliers, the regional value content or tariff shift rule may be broken before the resin reaches pellet form. At the heading level, Chapter 39 Note 6 requires classification according to the predominant monomer by weight; an ethylene-propylene elastomer with propylene as the predominant monomer belongs to heading 3902, even if it contains ethylene.

When filled concentrates, masterbatches, or chemically modified resins move out of 3901.40

Primary-form classification under heading 3901 does not remain valid for every LLDPE-based commercial form. A talc-filled compound containing 40 wt% inorganic filler may be classified outside 3901.40 when the product no longer has the character of a polymer in primary form; customs authorities may place it in a heading for preparations or plastics-based filler compounds under Chapter 3824 or a similar national provision. Pigment masterbatches based on LLDPE carrier resin containing 50–70 wt% carbon black, titanium dioxide, or organic pigments often leave the polymer heading because the added substance predominates by mass or imparts a distinct functional character. A flame-retardant compound containing LLDPE, 35 wt% ammonium polyphosphate, and 5 wt% pentaerythritol may be classified as a chemical preparation if the flame-retardant system determines the essential character under GRI 3(b). In contrast, an LLDPE pellet with a conventional antioxidant package such as 0.05–0.15 wt% hindered phenol and 0.05–0.10 wt% phosphite stabilizer remains within 3901.40 because the additives are present only to preserve the polymer during processing, not to modify the product for a specialized end-use.

Maleic anhydride-grafted LLDPE is a chemically modified polymer. The presence of grafted functionality does not automatically remove the product from heading 3901 if the material remains in primary form and the base polymer is still a polymer of ethylene; however, the subheading must be determined after the modification because the grafted polar functionality can affect the explanatory scope of 3901.90 or a national statistical breakout. An ethylene-alpha-olefin copolymer with a grafted maleic anhydride level of 0.5–1.5 wt% may be classified under 3901.90 in some customs rulings when the product is no longer described by the simple copolymer term. The importer should obtain a binding ruling before entering such materials. The same caution applies to silane-grafted moisture-crosslinkable LLDPE compounds used in wire and cable insulation; after silane grafting and catalyst masterbatch addition, the product may be considered a compounded or chemically modified preparation rather than a simple primary-form resin.

Entry documentation and binding ruling evidence prevent costly post-entry reclassification

Customs auditors evaluate LLDPE classification through commercial invoice descriptors, mill test certificates, safety data sheets, and laboratory submissions. A defensible entry package for 3901.40 should include the supplier’s batch-level certificate of analysis stating density by ISO 1183-1 or ASTM D792, melt flow rate by ISO 1133-1:2022 or ASTM D1238, comonomer type and content by ASTM D5017 or equivalent 13C NMR, and the product designation under ISO 1872-1, such as PE-LLD, followed by density and MFR digits. The safety data sheet should identify the resin as polyethylene CAS 9002-88-4, with the comonomer listed when relevant. A country-of-origin certificate alone is not classification evidence; it may state a six-digit HS code that the exporter copied from a prior shipment without testing. In the European Union, a Binding Tariff Information is legally binding under Article 33 of Regulation (EU) No 952/2013; in the United States, CBP binding rulings published in the Customs Rulings Online Search System provide the analogous national guidance. Where no binding ruling exists for the grade, the importer should preserve a classification rationale memorandum that cites GRI 1 and GRI 6, identifies the alpha-olefin comonomer, records the specific gravity test result to four decimal places, and states why the product is not excluded from heading 3901 by Chapter 39 Note 4 primary-form limitations.

Post-entry audits may request a retained sample of the actual import lot. Polymer pellets from different production campaigns can be visually identical but differ in comonomer, density, or melt rheology when bin blending is poor. Polyethylene does not require aggressive moisture protection because moisture regain is below 0.01% at 23 °C/50% RH; however, samples should be isolated from sunlight and high-temperature storage above 60 °C to avoid thermal oxidation that shifts density or generates carbonyl absorbances that interfere with FTIR interpretation. For long-term audit defense, retain the actual pellet sample, the density-gradient column raw data, the NMR spectrum, and the FTIR spectrum. Electronic records that show only “density: 0.920” without method, temperature, or instrument identification are weaker evidence and may be rejected in an origin or classification dispute. Trade remedy scope for polyethylene can use density, comonomer, melt index, and film-grade descriptors; classification under 3901.40 is separate from anti-dumping duty or countervailing duty scope. The importer should screen active trade remedy orders for the country of export before entry.

Published tariff treatment for 3901.40 is not globally uniform because national customs administrations assign 8-digit or 10-digit statistical suffixes, free-trade quotas, and anti-dumping or countervailing duty orders at the national level. A six-digit classification, even when correct, does not determine the final duty. For lot-level shipments at density values between 0.9395 g/cm³ and 0.9405 g/cm³, each lot must be separately supported by a documented density test; a single supplier certificate for multiple production campaigns is not acceptable audit evidence when the result straddles the subheading boundary. Entries lacking a batch-specific comonomer analysis remain structurally unverified for 3901.40 and are exposed to reclassification. The operational boundary includes not only density and comonomer identity but also the primary-form limitation of Chapter 39 Note 4: any LLDPE converted into film, sheet, fiber, or a fabricated article is outside heading 3901 regardless of the resin’s original grade.