Natural polymers (for example, alginic acid) and modified natural polymers (for example, hardened proteins, chemical derivatives of natural rubber), not elsewhere specified or included, in primary forms
5 declarable lines
Heading 3913 covers natural polymers and modified natural polymers that are not classified elsewhere, as long as they are in primary forms such as powders, granules, lumps or blocks. The heading splits into alginic acid and its salts and esters in 3913.10, and everything else in 3913.90. The 3913.90 lines separate chemical derivatives of natural rubber, polysaccharides such as xanthan gum, and a residual other line.
Products in this heading
- Sodium alginate, a salt of alginic acid used as a thickener
- Propylene glycol alginate for beverage and food stabilizer use
- Xanthan gum powder in bulk bags or drums
- Chlorinated natural rubber for coatings and adhesives
- Dextran and other fermentation polysaccharides in primary form
- Chemically hardened proteins such as hardened gelatin in powder form
- Pullulan in granular form for film and coating applications
How to choose the right subheading
- Whether the polymer is natural or modified natural, rather than fully synthetic
- Whether the product is alginic acid or a salt or ester of it, which decides 3913.10
- Whether the product is a chemical derivative of natural rubber or a polysaccharide
- Whether the material is a polysaccharide other than alginate, which points to the xanthan gum line or the residual other line
- Whether the goods are in primary forms such as powder, granules or blocks rather than finished articles
Often confused with
- Heading 3912Carboxymethyl cellulose and other cellulose ethers
Cellulose and its chemical derivatives have their own heading even when used as thickeners.
- Heading 3906Acrylic thickeners such as polyacrylic acid
Synthetic acrylic polymers fall in 3906, not with natural polymers.
- Unhardened gelatin
Gelatin that has not been chemically hardened stays in the protein chapter, not chapter 39.
- Heading 4001Natural rubber latex, unmodified
Raw natural rubber is classified in chapter 40; only modified derivatives reach 3913.
- Heading 3915Waste and scrap of plastics
Off-grade or scrap polymer material is covered by 3915 rather than by primary forms.
Frequently asked questions
What is the HTS code for xanthan gum?
Xanthan gum is classified under 3913.90.20.15, with a general (MFN) rate of 5.8%.
What is the duty on sodium alginate?
Sodium alginate and other salts and esters of alginic acid fall under 3913.10.00.00, which carries a general (MFN) rate of 4.2%.
How do I classify chlorinated natural rubber?
Chemical derivatives of natural rubber are covered by 3913.90.10.00 at a general (MFN) rate of Free. Other modified natural polymers not named in the specific lines fall to 3913.90.50.00 at 6.5%.
Guide written from the official schedule text. Rates quoted are general (MFN) rates; check the line page for trade agreement rates and the classification of your exact product.