Product classification

HS code for Silicone: 3910.00

Silicones, in primary forms.

Classification of silicone under HS 3910.00

Silicone is classified under HS code 3910.00 because it falls within Chapter 39, which covers plastics and articles thereof. Specifically, heading 3910 is reserved for silicones in primary forms. According to the Harmonized System Explanatory Notes, silicones are defined as non-chemically defined products containing in the molecule more than one silicon-oxygen-silicon link and containing organic groups connected to the silicon atoms by direct silicon-carbon bonds. To be classified here, the material must be in a primary form, such as liquids, pastes, blocks, lumps, or powders, as defined in Note 6 to Chapter 39. This classification is determined by the chemical structure of the polymer rather than its end-use, provided it has not been further worked into a finished article or a specific preparation like a sealant.

Covers
  • Silicone oils and fluids used as lubricants or heat-transfer media
  • Silicone resins in liquid or powder form
  • Silicone elastomers and gums before vulcanization
  • Silicone emulsions and dispersions
  • Silicone pastes used for industrial molding
Also under 3910.00
  • Dow Corning Silicones
  • Wacker Silicones
  • Shin-Etsu Silicones
  • Momentive Silicones

Codes often confused with 3910.00

Common mistake. Silicone products are frequently misclassified under HS code 3214.10, which covers glues and mastics. While silicone sealants are often referred to as "silicone," they are preparations containing fillers and are ready for use as caulking compounds, placing them in 3214. Silicone lubricants containing less than 70% petroleum oil might also be confused with 3403.99. Furthermore, silanes, which are the chemical precursors to silicones but do not contain the Si-O-Si chain, are classified as separate chemically defined compounds under heading 2931.90.

3214.10Mastics; painters' fillings32.14Glaziers' putty, grafting putty, resin cements, caulking compounds and other mastics; painters' fillings; non-refractory surfacing preparations for facades, indoor walls, floors, ceilings or the like3403.99Lubricating preparations; other than for the treatment of textile and similar materials, not containing petroleum oils or oils obtained from bituminous minerals2931.90Organo-inorganic compounds; other than tetramethyl lead, tetraethyl lead, tributyltin compounds, and other organo-phosphorous derivatives

Top exporters and importers of HS 391000 (the code used for silicone), 2025

In 2025, the largest exporter of HS 391000 (the code used for silicone) in UN Comtrade data was the United States, with 21% of world exports; the largest importer in UN Comtrade data was China, with 9.8% 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 391000, not only silicone.

Top exporters 2025 · share of world exports

  1. 1 United States $1.4B
  2. 2 China $1.4B
  3. 3 Japan $753M

World total: $6.5B Reported figures on UN Comtrade ↗

Top importers 2025 · share of world imports

  1. 1 China $813M
  2. 2 United States $673M
  3. 3 South Korea $489M

World total: $8.3B 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 silicone

Brazil splits HS 3910.00 into 8 NCM codes. Pick the one that matches your product:

Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.

Questions about silicone

What is the HS code for Silicone?

The HS code for Silicone is 391000 (Silicones; in primary forms). The primary HS code for silicone in its raw or primary form is 3910.00.

How do I classify Silicone for customs?

Silicone is classified under HS code 391000 — Silicones; in primary forms. This is a 6-digit subheading level code.

Is silicone rubber classified under the same code?

If the silicone rubber is in a primary form (unvulcanized gum or paste), it remains in 3910.00. However, if it has been vulcanized and shaped into sheets, tubes, or profiles, it is classified in Chapter 40 (Rubber) or elsewhere in Chapter 39 depending on its specific composition and form.

Which countries are the top exporters of silicone (HS 391000)?

In 2025, the top exporters of HS 391000 (the code used for silicone) in UN Comtrade data were the United States ($1.4B, 21% of world exports), China ($1.4B) and Japan ($753M). World exports came to about $6.5B, 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 silicone (HS 391000)?

In 2025, the top importers of HS 391000 (the code used for silicone) in UN Comtrade data were China ($813M, 9.8% of world imports), the United States ($673M) and South Korea ($489M). World imports came to about $8.3B, 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 Silicone the same in all countries?

The base HS code 391000 for Silicone 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 silicone in Brazil?

Brazil splits HS 391000 into 8 NCM codes, so the right one for silicone depends on the product's details: 3910.00.11 (Silicone oil prepolymer mixtures, MW up to 8,800), 3910.00.12 (Polydimethylsiloxane/PMHS oils in dispersion), 3910.00.13 (Dimethylsiloxane-vinyl oils, 1,000,000 cSt or more), 3910.00.19 (Other silicone oils), 3910.00.21 (Hot-vulcanising silicone elastomers), 3910.00.29 (Other silicone elastomers), and more.