HS code · 6-digit subheading
HS Code 3910.00 – Silicones; in primary forms
HS code 3910.00 is the 6-digit subheading for silicones, in primary forms. It is used for silicone oils, silicone elastomers (HTV, RTV), silicone resins, silicone emulsions and silicone greases.
What HS 3910.00 covers
This HS code encompasses silicones in primary forms, which are synthetic polymers characterized by their silicon-oxygen backbone. Traded as liquids, pastes, powders, or granules, silicones are highly valued in international commerce for their unique properties: excellent thermal stability, water repellency, electrical insulation, and flexibility across a wide temperature range. They are critical in diverse industries, including electronics, construction, automotive, healthcare, and personal care. Major importers are manufacturers producing sealants, adhesives, lubricants, coatings, medical devices, and cosmetic ingredients. Exporters are typically specialized chemical companies. The global trade in silicones is substantial, driven by their indispensable role in high-performance applications and their ability to enhance product durability, safety, and functionality across numerous sectors.
- Covers
- Silicone oils
- Silicone elastomers (HTV, RTV)
- Silicone resins
- Silicone emulsions
- Silicone greases
- Silicone powders
- Silicone gels
- Silicone sealants (bulk)
- Examples
- Dow Corning Silicones
- Wacker Silicones
- Shin-Etsu Silicones
- Momentive Silicones
Codes often confused with 3910.00
Common mistake. Can be confused with other synthetic polymers if not clearly identified by their silicon-oxygen backbone, or with finished silicone articles like gaskets (Chapter 40) or medical tubing (Chapter 90) if not in primary forms.
Top exporters and importers of HS code 391000, 2025
In 2025, the largest exporter of HS code 391000 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.
Top exporters 2025 · share of world exports
- 1 United States $1.4B 21% of world exports
- 2 China $1.4B 21% of world exports
- 3 Japan $753M 12% of world exports
World total: $6.5B Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 China $813M 9.8% of world imports
- 2 United States $673M 8.1% of world imports
- 3 South Korea $489M 5.9% of world imports
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 3910.00 8
Brazil splits HS 3910.00 into 8 NCM codes, Mercosur's 8-digit tariff lines.
- 3910.00.1 OilsÓleos Group
- 3910.00.11 Silicone oil prepolymer mixtures, MW up to 8,800Misturas de pré-polímeros lineares e cíclicos, obtidos por hidrólise de dimetildiclorosilano, de peso molecular médio inferior ou igual a 8.800
- 3910.00.12 Polydimethylsiloxane/PMHS oils in dispersionPolidimetilsiloxano, polimetilidrogenosiloxano ou misturas destes produtos, em dispersão
- 3910.00.13 Dimethylsiloxane-vinyl oils, 1,000,000 cSt or moreCopolímeros de dimetilsiloxano com compostos vinílicos, de viscosidade igual ou superior a 1.000.000 cSt
- 3910.00.19 Other silicone oilsOutros
- 3910.00.2 ElastomersElastômeros Group
- 3910.00.21 Hot-vulcanising silicone elastomersDe vulcanização a quente
- 3910.00.29 Other silicone elastomersOutros
- 3910.00.30 Silicone resins in primary formsResinas
- 3910.00.90 Other silicones in primary formsOutros
All Brazil NCM codes in heading 39.10 →
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text is official; the English is our translation.
Questions about HS 3910.00
What is HS code 391000?
HS code 391000 is a 6-digit subheading in the Harmonized System that covers: Silicones; in primary forms. This HS code encompasses silicones in primary forms, which are synthetic polymers characterized by their silicon-oxygen backbone. Traded as liquids, pastes, powders, or granules, silicones are highly valued in international commerce for their unique properties: excellent thermal stability, water repellency, electrical insulation, and flexibility across a wide temperature range. They are critical in diverse industries, including electronics, construction, automotive, healthcare, and personal care. Major importers are manufacturers producing sealants, adhesives, lubricants, coatings, medical devices, and cosmetic ingredients. Exporters are typically specialized chemical companies. The global trade in silicones is substantial, driven by their indispensable role in high-performance applications and their ability to enhance product durability, safety, and functionality across numerous sectors.
What products fall under HS code 391000?
Silicone oils, Silicone elastomers (HTV, RTV), Silicone resins, Silicone emulsions, Silicone greases, Silicone powders, Silicone gels, Silicone sealants (bulk)
What are common misclassifications for HS code 391000?
Can be confused with other synthetic polymers if not clearly identified by their silicon-oxygen backbone, or with finished silicone articles like gaskets (Chapter 40) or medical tubing (Chapter 90) if not in primary forms.
Which countries are the top exporters of goods under HS code 391000?
In 2025, the top exporters of HS code 391000 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 goods under HS code 391000?
In 2025, the top importers of HS code 391000 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.
How is HS code 391000 structured?
HS code 391000 is a 6-digit subheading under the Harmonized System. The first 2 digits (39) identify the chapter, digits 3-4 (10) identify the heading, and digits 5-6 (00) specify the subheading. This code is standardized globally by the World Customs Organization.
What is the Brazil NCM code for HS code 391000?
Brazil splits HS code 391000 into 8 NCM codes: 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), 3910.00.30 (Silicone resins in primary forms), 3910.00.90 (Other silicones in primary forms). The first 6 digits of each match the HS code.