Product classification
HS code for Carboxymethylcellulose: 3912.31
Cellulose ethers, carboxymethylcellulose and its salts, in primary forms.
Classification of carboxymethylcellulose under HS 3912.31
Carboxymethylcellulose (CMC) and its salts are classified under HS code 391231. This substance is a chemical derivative of cellulose, specifically a cellulose ether, where carboxymethyl groups are bound to some of the hydroxyl groups of the glucopyranose monomers. It is produced by the reaction of cellulose with alkali and chloroacetic acid. Under the Harmonized System, Chapter 39 covers plastics and polymers. Heading 3912 is dedicated to cellulose and its chemical derivatives not elsewhere specified. Subheading 391231 specifically identifies carboxymethylcellulose and its salts, such as Sodium CMC. To fall under this code, the product must be in a "primary form," which according to Note 6 to Chapter 39 includes liquids, pastes, blocks, irregular shapes, lumps, powders, granules, and flakes. CMC is widely used as a rheology modifier, thickener, and stabilizer in food (E466), pharmaceuticals, and industrial applications like oil drilling muds. The classification remains the same regardless of the grade (technical, purified, or food grade) as long as it remains a primary form of the polymer.
- Covers
- Sodium carboxymethylcellulose (NaCMC)
- Purified CMC powder
- Technical grade CMC granules
- CMC salts in primary forms
- Carboxymethylcellulose solutions in water (primary form)
- Also under 3912.31
- Ashland Aqualon CMC
- Dow Walocel CMC
- CP Kelco Finnfix CMC
- DuPont Tylose CMC
- AkzoNobel Bermocoll CMC
Codes often confused with 3912.31
Common mistake. CMC is sometimes misclassified under 391239, which is the residual category for "other" cellulose ethers like Methylcellulose or Hydroxypropyl cellulose. Because CMC has its own specific subheading (391231), using 391239 is an error. It may also be confused with 3402 if it is part of a prepared detergent mixture, but as a pure chemical derivative in primary form, 391231 is correct.
Top exporters and importers of HS 391231 (the code used for carboxymethylcellulose), 2025
In 2025, the largest exporter of HS 391231 (the code used for carboxymethylcellulose) in UN Comtrade data was China, with 27% of world exports; the largest importer in UN Comtrade data was the United States, with 12% of world imports. Countries that did not report 2025 data are estimated from partner records, which can understate them.
Figures cover everything classified under HS 391231, not only carboxymethylcellulose.
Top exporters 2025 · share of world exports
- 1 China $269M 27% of world exports
- 2 Finland $134M 14% of world exports
- 3 Netherlands $85M 8.6% of world exports
World total: $988M Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 United States $130M 12% of world imports
- 2 India $78M 7.3% of world imports
- 3 China $62M 5.8% of world imports
World total: $1.1B Reported figures on UN Comtrade ↗
How these figures are built
109 countries reported 2025 trade to UN Comtrade in HS 2022, and their own totals are used. Countries that did not report are estimated from what other countries recorded trading with them. Those estimates miss trade with other non-reporting countries, so they can be low, and a non-reporting country can rank higher than shown or be missing from the list. World totals add both and leave out trade between two non-reporting countries. Figures are in current US dollars; reported imports are mostly valued CIF and exports FOB, and exports include re-exports. The UN Comtrade links show the underlying records; they can also list a few reporters left out here (regional groups and older HS editions).
Source: UN Comtrade (United Nations Statistics Division), 2025 annual data.
Brazil NCM codes for carboxymethylcellulose
Brazil splits HS 3912.31 into 4 NCM codes. Pick the one that matches your product:
- 3912.31.11Carboxymethylcellulose, CMC content 75% or more
- 3912.31.19Carboxymethylcellulose, CMC content below 75%
- 3912.31.21Carboxymethylcellulose salts, content 75% or more
- 3912.31.29Carboxymethylcellulose salts, content below 75%
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.
Questions about carboxymethylcellulose
What is the HS code for Carboxymethylcellulose?
The HS code for Carboxymethylcellulose is 391231 (Cellulose ethers; carboxymethylcellulose and its salts, in primary forms). The HS code for Carboxymethylcellulose and its salts in primary forms is 391231.
How do I classify Carboxymethylcellulose for customs?
Carboxymethylcellulose is classified under HS code 391231 — Cellulose ethers; carboxymethylcellulose and its salts, in primary forms. This is a 6-digit subheading level code.
Does this code include food-grade CMC?
Yes, food-grade CMC is classified under 391231, provided it is in a primary form like powder or granules and not mixed into a finished food preparation.
Which countries are the top exporters of carboxymethylcellulose (HS 391231)?
In 2025, the top exporters of HS 391231 (the code used for carboxymethylcellulose) in UN Comtrade data were China ($269M, 27% of world exports), Finland ($134M) and the Netherlands ($85M). World exports came to about $988M, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.
Which countries are the top importers of carboxymethylcellulose (HS 391231)?
In 2025, the top importers of HS 391231 (the code used for carboxymethylcellulose) in UN Comtrade data were the United States ($130M, 12% of world imports), India ($78M) and China ($62M). World imports came to about $1.1B, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.
Is the HS code for Carboxymethylcellulose the same in all countries?
The base HS code 391231 for Carboxymethylcellulose is internationally standardized for the first 6 digits across 200+ countries. Individual countries may add additional digits for national tariff lines and specific classifications.
What is the NCM code for carboxymethylcellulose in Brazil?
Brazil splits HS 391231 into 4 NCM codes, so the right one for carboxymethylcellulose depends on the product's details: 3912.31.11 (Carboxymethylcellulose, CMC content 75% or more), 3912.31.19 (Carboxymethylcellulose, CMC content below 75%), 3912.31.21 (Carboxymethylcellulose salts, content 75% or more), 3912.31.29 (Carboxymethylcellulose salts, content below 75%).