What is HS-4 3913 used for?
Use this as a comparison hint, then confirm the final decision with legal notes and country-specific rules.
HS-4 · Heading
3913 — Natural polymers (e.g. alginic acid) and modified natural polymers (e.g. hardened proteins, chemical derivatives of natural rubber), n.e.c. or included, in primary forms
Chapter 39: Plastics and articles thereof
Plain-language overview
Use HS-4 3913 when importing natural polymers like alginic acid or modified natural polymers in primary forms. For instance, if you're shipping alginic acid for use in food processing or pharmaceuticals, this heading applies directly to your product.
When deciding between HS-6 codes, note that 391310 specifically covers alginic acid and its derivatives. If your product is alginic acid in any form, including salts or esters, this is your code. However, if your natural polymer is not alginic acid, such as a modified protein or another polymer, you would use 391390.
Both subheadings under HS-4 3913 deal with natural and modified polymers, but they differ significantly in content. 391390 encompasses all other natural and modified polymers not classified as alginic acid, which could include substances derived from natural rubber or other plant sources.
Keywords & topics
Useful terms traders and brokers use for this HS-4 heading.
natural polymers · modified natural polymers · alginic acid imports · primary forms of polymers · chemical derivatives of natural rubber · polymers in food processing · hardened proteins · natural polymer classification · HS-4 3913 · HS-6 391310 · HS-6 391390
Examples
Drawn from the official tariff wording for this HS-4 heading. Always confirm against your published schedule and legal notes.
- Alginic acid for use in food additives
- Hardened proteins used in cosmetics
- Chemical derivatives of natural rubber for industrial applications
- Natural polymers for pharmaceutical formulations
- Modified starches for food processing
- Plant-based polymers for biodegradable packaging
Common questions
Frequent classification questions with short practical guidance.
How to classify alginic acid for import?
Write down material, use, and product form first, then compare nearby lines before you lock the code.
What are modified natural polymers?
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Which HS code for natural polymers?
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Differences between HS-6 391310 and 391390?
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What products fall under HS-4 3913?
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Related topics
Common real-world topics that come up during code comparison.
how to import alginic acid under HS-4 3913
Check the exact product specs and destination-country tariff notes before finalizing the code.
classification of natural polymers for customs
Check the exact product specs and destination-country tariff notes before finalizing the code.
understanding HS-6 codes for modified natural polymers
Use this topic to narrow your shortlist, then validate the final code against legal wording.
examples of products classified under HS-4 3913
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requirements for importing natural polymers
Check the exact product specs and destination-country tariff notes before finalizing the code.
differences in HS codes for alginic acid
Compare adjacent HS lines and pick the one that matches material, function, and product form most closely.
how to determine the correct HS code for polymers
Use this topic to narrow your shortlist, then validate the final code against legal wording.
shipping natural and modified polymers internationally
Use this topic to narrow your shortlist, then validate the final code against legal wording.
Questions & answers
For orientation only—the binding text is your national tariff and the WCO nomenclature your country uses.
- What products are classified under HS-4 3913?
- HS-4 3913 includes natural polymers like alginic acid and modified natural polymers in primary forms, such as hardened proteins and derivatives of natural rubber.
- How do I know if my product falls under HS-6 391310 or 391390?
- If your product is alginic acid or its derivatives, use HS-6 391310. For all other natural or modified polymers, use HS-6 391390.
- Are there specific import regulations for HS-4 3913?
- Yes, products under HS-4 3913 may require specific documentation and compliance with food safety or chemical regulations, depending on their end use.
- Can I use HS-4 3913 for food-grade alginic acid?
- Yes, HS-4 3913 is suitable for food-grade alginic acid, but ensure it meets all relevant food safety standards for import.
- What is the difference between natural and modified natural polymers?
- Natural polymers are derived directly from plants or animals, while modified natural polymers have undergone chemical changes to enhance their properties or functionality.
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Heading-browse mode uses HS-6 391300 (first line of this block).