Chapter 39 covers plastics and articles thereof, namely natural or synthetic high molecular compounds obtained by polymerization or other similar methods. This chapter includes polymers in primary forms (such as resins, granules, powders, etc.), as well as waste and scrap and semi-finished products. Note, however, that this chapter does not include natural rubber (Chapter 40), paper products (Chapter 48), or textile materials (Chapters 50-60). As for alginic acid and its salts and esters, they are natural high molecular compounds and remain classified in this chapter even after chemical modification. Heading 3913 covers natural polymers (such as alginic acid, chitin, pectin, etc.) and their derivatives, including alginic acid, alginates, and alginic acid esters in primary forms. These substances are usually extracted from seaweed and obtained through chemical processing, and are used in the food, pharmaceutical, textile, and other industries. This heading explicitly lists alginic acid and its salts and esters as subheading 3913.10, distinguishing them from other natural polymers such as starch derivatives (heading 3505) or cellulose derivatives (heading 3912). First 2 digits 39: represents Chapter 39, namely plastics and articles thereof. Digits 3-4, 13: represents heading 3913, specifically natural polymers and their modified forms, including alginic acid, chitin, pectin, etc. Digits 5-6, 10: represents subheading 3913.10, specifically referring to alginic acid and its salts and esters in primary forms. Here 'primary forms' refers to unprocessed forms such as liquid, paste, block, powder, granule, etc., and does not include articles already made into finished or semi-finished products. This commodity is alginic acid and its salts and esters, which are natural high molecular compounds and still possess plastic properties after chemical modification, and are therefore classified in Chapter 39. Since the specific variety is alginic acid, it is classified under heading 3913, rather than other natural polymers such as chitin (3913.90) or cellulose (3912). At the same time, subheading 3913.10 explicitly lists alginic acid and its salts and esters, so it is not classified under other subheadings.
Chapter
Chapter 39 covers plastics and articles thereof, namely natural or synthetic high molecular compounds obtained by polymerization or other similar methods. This chapter includes polymers in primary forms (such as resins, granules, powders, etc.), as well as waste and scrap and semi-finished products. Note, however, that this chapter does not include natural rubber (Chapter 40), paper products (Chapter 48), or textile materials (Chapters 50-60). As for alginic acid and its salts and esters, they are natural high molecular compounds and remain classified in this chapter even after chemical modification.
Heading
Heading 3913 covers natural polymers (such as alginic acid, chitin, pectin, etc.) and their derivatives, including alginic acid, alginates, and alginic acid esters in primary forms. These substances are usually extracted from seaweed and obtained through chemical processing, and are used in the food, pharmaceutical, textile, and other industries. This heading explicitly lists alginic acid and its salts and esters as subheading 3913.10, distinguishing them from other natural polymers such as starch derivatives (heading 3505) or cellulose derivatives (heading 3912).
Digit Breakdown
First 2 digits 39: represents Chapter 39, namely plastics and articles thereof. Digits 3-4, 13: represents heading 3913, specifically natural polymers and their modified forms, including alginic acid, chitin, pectin, etc. Digits 5-6, 10: represents subheading 3913.10, specifically referring to alginic acid and its salts and esters in primary forms. Here 'primary forms' refers to unprocessed forms such as liquid, paste, block, powder, granule, etc., and does not include articles already made into finished or semi-finished products.
Classification Basis
This commodity is alginic acid and its salts and esters, which are natural high molecular compounds and still possess plastic properties after chemical modification, and are therefore classified in Chapter 39. Since the specific variety is alginic acid, it is classified under heading 3913, rather than other natural polymers such as chitin (3913.90) or cellulose (3912). At the same time, subheading 3913.10 explicitly lists alginic acid and its salts and esters, so it is not classified under other subheadings.
📝 Declaration Elements
Product Name: Fill in the standard name of the commodity, such as 'alginic acid', 'sodium alginate', 'propylene glycol alginate', etc., which must correspond to the HS code. Composition and Content: Indicate the main components and content, such as alginic acid content, type of salt base (sodium, potassium, calcium, etc.), degree of esterification, etc. Appearance: Describe the physical form, such as powder, granule, paste, liquid, etc., to confirm whether it conforms to 'primary forms'. Source: Explain the source of raw materials, such as extraction from brown algae including kelp and sargassum, which helps confirm the natural polymer attribute. Use: Fill in the main application fields, such as food thickener, pharmaceutical excipient, printing and dyeing auxiliary, etc., to assist classification. Packaging Specifications: Indicate the packaging form and net weight, such as 25kg paper bag, 500g bottle, etc., which affects whether it is retail packaging. Brand: If there is a brand, declare the brand name; if there is no brand, fill in 'None'. Model: Fill in the product model or grade, such as food grade, pharmaceutical grade, industrial grade, etc.; different grades may affect regulatory conditions. Customs declaration example:
Product Name: Sodium Alginate
Composition and Content: Sodium alginate ≥99%, moisture ≤1%
Appearance: White powder
Source: Extracted from kelp
Use: Food thickener
Packaging Specifications: 25kg/bag, non-retail packaging
Brand: None
Model: Food grade
HS Code: 3913100000 Mistakenly classifying alginic acid esters under 2918 (carboxylic acid esters), but alginic acid esters are polymers and should be classified under 3913. Declaring prepared food additives (such as compound thickeners) under 3913, when they may actually be classified under 2106. Ignoring the 'primary forms' requirement and classifying alginic acid fibers or films (already formed) under 3913, when they should actually be classified under 3915 or 3920.
Product Name
Fill in the standard name of the commodity, such as 'alginic acid', 'sodium alginate', 'propylene glycol alginate', etc., which must correspond to the HS code.
⚠️ Mistakenly writing 'seaweed acid' or 'kelp gum', but the latter are common names; the standardized chemical name should be used.
Composition and Content
Indicate the main components and content, such as alginic acid content, type of salt base (sodium, potassium, calcium, etc.), degree of esterification, etc.
⚠️ Writing only 'alginic acid' without specifying the exact type of salt or ester, leading to classification errors.
Appearance
Describe the physical form, such as powder, granule, paste, liquid, etc., to confirm whether it conforms to 'primary forms'.
⚠️ Declaring products already tableted or made into capsules as primary forms, when they should actually be classified under other headings.
Source
Explain the source of raw materials, such as extraction from brown algae including kelp and sargassum, which helps confirm the natural polymer attribute.
⚠️ Failure to indicate the source may lead to it being mistaken for a synthetic polymer.
Use
Fill in the main application fields, such as food thickener, pharmaceutical excipient, printing and dyeing auxiliary, etc., to assist classification.
⚠️ The description of use is too broad, such as 'industrial use', which cannot provide effective classification information.
Packaging Specifications
Indicate the packaging form and net weight, such as 25kg paper bag, 500g bottle, etc., which affects whether it is retail packaging.
⚠️ Ignoring packaging specifications may lead to classification under other codes for retail packaging.
Brand
If there is a brand, declare the brand name; if there is no brand, fill in 'None'.
⚠️ Confusing the brand with the manufacturer, or omitting the brand, leading to intellectual property issues.
Model
Fill in the product model or grade, such as food grade, pharmaceutical grade, industrial grade, etc.; different grades may affect regulatory conditions.
⚠️ The model does not match the use, such as mistakenly declaring pharmaceutical grade as industrial grade.
Mistakenly classifying alginic acid esters under 2918 (carboxylic acid esters), but alginic acid esters are polymers and should be classified under 3913.
Declaring prepared food additives (such as compound thickeners) under 3913, when they may actually be classified under 2106.
Ignoring the 'primary forms' requirement and classifying alginic acid fibers or films (already formed) under 3913, when they should actually be classified under 3915 or 3920.
🎯 Classification Logic
Core criteria for classification: 1) The product is a natural high molecular compound, conforming to the notes to Chapter 39; 2) The specific variety is alginic acid and its salts and esters, conforming to the description of heading 3913; 3) The form is primary forms, not processed into finished products; 4) Non-retail packaging; if retail packaging, it may be classified under other headings (such as 3505 or 3824). At the same time, reference should be made to the detailed explanations of 3913 in the 'Explanatory Notes to the Harmonized System' to confirm the scope of alginic acid derivatives. 391390 Other natural polymers: This code covers chitin, pectin, agar, etc., but does not include alginic acid. Alginic acid has a specific subheading 3913.10, so it is not classified under 3913.90. 391231 Carboxymethylcellulose and its salts: Cellulose derivatives are classified under 3912, while alginic acid derivatives are classified under 3913. They have different sources and different chemical structures. 350510 Dextrin and other modified starches: Modified starches are classified under Chapter 35, while alginic acid is a natural polymer classified under Chapter 39. Their sources and chemical compositions are different. 291813 Tartrates and esters: Small-molecule organic acid salts are classified under Chapter 29, while alginic acid is a macromolecular polymer and should be classified under Chapter 39. 382499 Other chemical products: If the alginic acid product is a compounded chemical, it may be classified under 3824, but single-component alginic acid is still classified under 3913. Is the product in primary forms (powder, granule, liquid, etc.)? Is the product alginic acid or its salts/esters, rather than other natural polymers? Is the product a single component, rather than a compounded additive? Is the packaging non-retail packaging? Have more specific chapters such as Chapter 29 and Chapter 35 been excluded?
Basis
Core criteria for classification: 1) The product is a natural high molecular compound, conforming to the notes to Chapter 39; 2) The specific variety is alginic acid and its salts and esters, conforming to the description of heading 3913; 3) The form is primary forms, not processed into finished products; 4) Non-retail packaging; if retail packaging, it may be classified under other headings (such as 3505 or 3824). At the same time, reference should be made to the detailed explanations of 3913 in the 'Explanatory Notes to the Harmonized System' to confirm the scope of alginic acid derivatives.
Confused Codes：
391390 - Other natural polymers
This code covers chitin, pectin, agar, etc., but does not include alginic acid. Alginic acid has a specific subheading 3913.10, so it is not classified under 3913.90.
391231 - Carboxymethylcellulose and its salts
Cellulose derivatives are classified under 3912, while alginic acid derivatives are classified under 3913. They have different sources and different chemical structures.
350510 - Dextrin and other modified starches
Modified starches are classified under Chapter 35, while alginic acid is a natural polymer classified under Chapter 39. Their sources and chemical compositions are different.
291813 - Tartrates and esters
Small-molecule organic acid salts are classified under Chapter 29, while alginic acid is a macromolecular polymer and should be classified under Chapter 39.
382499 - Other chemical products
If the alginic acid product is a compounded chemical, it may be classified under 3824, but single-component alginic acid is still classified under 3913.
Self-Check：
✓ Is the product in primary forms (powder, granule, liquid, etc.)?
✓ Is the product alginic acid or its salts/esters, rather than other natural polymers?
✓ Is the product a single component, rather than a compounded additive?
✓ Is the packaging non-retail packaging?
✓ Have more specific chapters such as Chapter 29 and Chapter 35 been excluded?
❓ FAQ
Are the HS codes for alginic acid and sodium alginate the same? Yes, alginic acid and its salts and esters are all classified under HS code 391310. This subheading explicitly includes alginic acid, sodium alginate, potassium alginate, calcium alginate, ammonium alginate, and alginic acid esters (such as propylene glycol alginate). However, note that if the product is a compounded food additive, it may be classified under other codes. How do you distinguish the HS codes for alginic acid and agar? Alginic acid is classified under 391310, while agar (a polysaccharide extracted from red algae) is classified under 391390. Both are natural polymers, but they are different specific varieties. Classification should be determined based on the product name and composition. Which code should propylene glycol alginate be classified under? Propylene glycol alginate is an alginic acid ester and should be classified under 391310. However, if it is compounded with other ingredients as an emulsifier, it may be classified under 3824 or 2106. When declaring, the composition and use must be indicated. What regulatory documents are required for importing alginic acid? When alginic acid is used as a food additive or pharmaceutical excipient, it may require a food additive inspection certificate, drug import registration certificate, etc. The specifics depend on the use and regulatory conditions. It is recommended to check the latest 'Customs Import and Export Tariff' and regulatory condition codes. What is the difference in HS codes between alginic acid powder and alginic acid fiber? Alginic acid powder is in primary forms and is classified under 391310; alginic acid fiber (already formed) is a semi-finished product or article and should be classified under 3915 (plastic waste and scrap) or 3920 (plastic plates, sheets, film), etc. The key to classification is whether it remains in primary forms. If the alginic acid product is in retail packaging, will the HS code change? Yes, if the alginic acid product is in retail packaging and directly for retail sale, it may be classified under other headings, such as 3505 (dextrin and modified starch) or 3824 (other chemical products). However, if it is still in primary forms and not for retail sale, it is classified under 391310. Judgment must be made based on packaging and use. How can I check the import tariff rate for alginic acid products? Tariff rates may change. It is recommended to check the latest rates through the official website of the General Administration of Customs, China International Trade Single Window, or the 'Import and Export Tariff'. At the same time, attention should be paid to free trade agreement rates, if applicable. What is the difference in HS codes between alginic acid and chitin? Alginic acid is classified under 391310, and chitin is classified under 391390. Both are natural polymers, but they are in different subheadings. Classification should be distinguished based on product name and source.
Q: Are the HS codes for alginic acid and sodium alginate the same?
A: Yes, alginic acid and its salts and esters are all classified under HS code 391310. This subheading explicitly includes alginic acid, sodium alginate, potassium alginate, calcium alginate, ammonium alginate, and alginic acid esters (such as propylene glycol alginate). However, note that if the product is a compounded food additive, it may be classified under other codes.
Q: How do you distinguish the HS codes for alginic acid and agar?
A: Alginic acid is classified under 391310, while agar (a polysaccharide extracted from red algae) is classified under 391390. Both are natural polymers, but they are different specific varieties. Classification should be determined based on the product name and composition.
Q: Which code should propylene glycol alginate be classified under?
A: Propylene glycol alginate is an alginic acid ester and should be classified under 391310. However, if it is compounded with other ingredients as an emulsifier, it may be classified under 3824 or 2106. When declaring, the composition and use must be indicated.
Q: What regulatory documents are required for importing alginic acid?
A: When alginic acid is used as a food additive or pharmaceutical excipient, it may require a food additive inspection certificate, drug import registration certificate, etc. The specifics depend on the use and regulatory conditions. It is recommended to check the latest 'Customs Import and Export Tariff' and regulatory condition codes.
Q: What is the difference in HS codes between alginic acid powder and alginic acid fiber?
A: Alginic acid powder is in primary forms and is classified under 391310; alginic acid fiber (already formed) is a semi-finished product or article and should be classified under 3915 (plastic waste and scrap) or 3920 (plastic plates, sheets, film), etc. The key to classification is whether it remains in primary forms.
Q: If the alginic acid product is in retail packaging, will the HS code change?
A: Yes, if the alginic acid product is in retail packaging and directly for retail sale, it may be classified under other headings, such as 3505 (dextrin and modified starch) or 3824 (other chemical products). However, if it is still in primary forms and not for retail sale, it is classified under 391310. Judgment must be made based on packaging and use.
Q: How can I check the import tariff rate for alginic acid products?
A: Tariff rates may change. It is recommended to check the latest rates through the official website of the General Administration of Customs, China International Trade Single Window, or the 'Import and Export Tariff'. At the same time, attention should be paid to free trade agreement rates, if applicable.
Q: What is the difference in HS codes between alginic acid and chitin?
A: Alginic acid is classified under 391310, and chitin is classified under 391390. Both are natural polymers, but they are in different subheadings. Classification should be distinguished based on product name and source.
⚠️ Disclaimer: HS code classification, declaration elements, tariff rates and regulatory conditions on this page are for reference only and do not constitute legal advice on customs classification. Tariff rates and regulations are subject to change; the latest announcements from the General Administration of Customs and on-site determinations shall prevail. Please consult professional customs brokers or customs authorities before import/export.