Chapter 39 covers plastics and articles thereof, and is a core chapter in the HS classification system organized by material properties. This chapter includes polymers in primary forms (such as resins and pellets), semi-manufactures (such as rods, tubes, and plates), and finished articles, but excludes rubber, textiles, machinery, and apparatus. Primary forms refer to unprocessed forms such as liquids, pastes, blocks, and powders, and are the basic raw materials of the plastics industry. The notes to this chapter provide detailed classification rules for copolymers, mixtures, and chemically modified polymers, and are the primary basis for determining polymer classification. Heading 3904 covers polymers of vinyl chloride or of other halogenated olefins, in primary forms, including homopolymers and copolymers. It is specifically divided into: 3904.10 polyvinyl chloride (not mixed with other substances), 3904.21/22 non-plasticized/plasticized polyvinyl chloride (mixed with other substances), 3904.30 vinyl chloride-vinyl acetate copolymers, 3904.40 other vinyl chloride copolymers, 3904.50 vinylidene chloride polymers, 3904.61/69 fluoropolymers, and 3904.90 other polymers of halogenated olefins. This heading is limited to primary forms and does not include waste and scrap or finished articles. The first 2 digits "39" represent Chapter 39, "Plastics and articles thereof," one of the largest material-based categories in the entire tariff schedule. The 3rd-4th digits "04" represent heading 3904, specifically "Polymers of vinyl chloride or of other halogenated olefins, in primary forms," which is further subdivided under this heading by polymer type and whether it is mixed. The 5th-6th digits "40" represent subheading 3904.40, namely "Other vinyl chloride copolymers," referring to all vinyl chloride copolymers other than vinyl chloride-vinyl acetate copolymers (3904.30), such as vinyl chloride-ethylene copolymers, vinyl chloride-propylene copolymers, and vinyl chloride-maleate copolymers. This subheading is a residual subheading covering vinyl chloride copolymers not elsewhere specified. The goods are a vinyl chloride copolymer and are in primary form, so they are classified under 3904. Since they are not a homopolymer (3904.10) or polyvinyl chloride mixed with other substances (3904.21/22), nor a vinyl chloride-vinyl acetate copolymer (3904.30), and certainly not a vinylidene chloride polymer (3904.50) or fluoropolymer (3904.61/69), they are classified under 3904.40, "Other vinyl chloride copolymers." If they were a copolymer of vinyl chloride and vinyl acetate, they would be classified under 3904.30.

Product name: The specific name of the declared goods, which should include the type of comonomer, such as "vinyl chloride-ethylene copolymer." Appearance: Describe the physical form of the primary shape, such as powder, granules, paste, or blocks. Composition content: The percentage content of each monomer unit, such as 80% vinyl chloride and 20% ethylene, as well as additive content. Types and proportions of monomer units: Clearly state the chemical names of the comonomers and their molar ratio or weight ratio. Brand: The brand name of the manufacturer or trader; if there is no brand, enter "none." Model: The manufacturer's product model or grade used to distinguish different specifications. Use: The final application field of the copolymer, such as coatings, adhesives, or films. Manufacturer: The name of the enterprise producing the goods, which must be consistent with the invoice and contract. Product name: Vinyl chloride-ethylene copolymer Appearance: White powder Composition content: Vinyl chloride 85%, ethylene 15% Types and proportions of monomer units: Vinyl chloride 85%, ethylene 15% Brand: None Model: VEC-100 Use: Used in the production of coatings Manufacturer: XX Chemical Co., Ltd. Failure to distinguish homopolymers from copolymers, incorrectly declaring vinyl chloride homopolymer as copolymer. Failure to provide the specific types and proportions of comonomers, making it impossible to determine the subheading. Incorrectly classifying polyvinyl chloride mixed with other substances (3904.21/22) under 3904.40. Ignoring the definition of primary forms and incorrectly declaring semi-manufactures or finished products.

The core basis for classification is the notes and subheading notes to Chapter 39 of the Import and Export Tariff. First determine whether the goods are in primary form, then determine the polymer type: if it is a vinyl chloride homopolymer, classify under 3904.10 (not mixed with other substances) or 3904.21/22 (mixed with other substances); if it is a vinyl chloride copolymer, then examine the comonomer: vinyl chloride-vinyl acetate copolymers are classified under 3904.30, and other vinyl chloride copolymers under 3904.40. Attention must be paid to the definitions of copolymers and polymer mixtures in the Chapter 39 notes, as well as the limitation of "primary forms." 3904.30 Vinyl chloride-vinyl acetate copolymers: Refers only to copolymers of vinyl chloride and vinyl acetate; other comonomers are not classified here. If the comonomer is vinyl acetate, classify under 3904.30; if it is another monomer, classify under 3904.40. 3904.10 Polyvinyl chloride, not mixed with other substances: Refers to vinyl chloride homopolymers not mixed with other substances. If it is a copolymer, even if not mixed with other substances, it is not classified under 3904.10. 3904.21 Non-plasticized polyvinyl chloride: Refers to vinyl chloride homopolymers mixed with other substances (such as plasticizers and stabilizers) and not plasticized. Copolymers are not classified here. 3904.50 Vinylidene chloride polymers: Refers to vinylidene chloride homopolymers or copolymers, which are different from vinyl chloride copolymers. If the monomer is vinylidene chloride, classify under 3904.50. 3901.10 Polymers of ethylene, in primary forms: If the ethylene content in a vinyl chloride-ethylene copolymer exceeds the vinyl chloride content, it may be classified under 3901.10. The monomer unit proportions must be compared in accordance with the Chapter 39 notes. Is it in primary form? Is it a vinyl chloride copolymer? Is the comonomer vinyl acetate? Is it mixed with other substances? Do the comonomer proportions affect classification?

How can it be determined whether a vinyl chloride copolymer should be classified under 3904.40? First confirm that the goods are in primary form and are a copolymer of vinyl chloride and other monomers. If the comonomer is not vinyl acetate and is not vinylidene chloride or a fluoropolymer, classify under 3904.40. If the comonomer is vinyl acetate, classify under 3904.30. What is the difference in classification between vinyl chloride-vinyl acetate copolymers and vinyl chloride-ethylene copolymers? Vinyl chloride-vinyl acetate copolymers are classified under 3904.30, while vinyl chloride-ethylene copolymers are classified under 3904.40. The difference lies in the type of comonomer; vinyl acetate has a dedicated subheading, while other comonomers fall under other subheadings. If a vinyl chloride copolymer is mixed with a plasticizer, how should it be classified? If it is mixed with substances such as plasticizers and is a vinyl chloride homopolymer, classify under 3904.21 or 3904.22. However, if it is a copolymer, even if mixed with other substances, it is still classified under 3904.30 or 3904.40, because subheadings 3904.21/22 apply only to homopolymers. How should "types and proportions of monomer units" be filled in at declaration? The chemical names and weight percentages or molar ratios of all comonomers should be provided, for example, "vinyl chloride 85%, ethylene 15%." The proportions should accurately reflect the actual composition to avoid classification disputes. Do goods under 3904.40 include vinyl chloride-maleate copolymers? Yes, vinyl chloride-maleate copolymers belong to other vinyl chloride copolymers and should be classified under 3904.40. However, it must be ensured that they are in primary form and are not listed under another more specific subheading. How can the import tariff rate for 3904.40 be checked? It can be checked in the Import and Export Tariff of the People's Republic of China or through the official website of the General Administration of Customs and China Customs' import and export commodity classification system. Tariff rates may vary depending on trade agreements, origin, and other factors, so consulting a professional customs broker is recommended. If the vinyl chloride content in a vinyl chloride copolymer is less than 50%, is it still classified under 3904? According to the Chapter 39 notes, copolymers should be classified according to the monomer unit that predominates by weight. If the vinyl chloride content is lower than that of other monomers, it may be classified under other headings, such as 3901 (polymers of ethylene). A specific analysis is required. What is the difference between 3904.40 and 3904.90? 3904.40 specifically refers to other vinyl chloride copolymers, while 3904.90 refers to other polymers of halogenated olefins, such as tetrafluoroethylene-hexafluoropropylene copolymers. The difference lies in whether the polymer is mainly based on vinyl chloride.