HS code · 6-digit subheading
HS Code 3907.91 – Polyesters; n.e.c. in heading no. 3907, unsaturated, in primary forms
HS code 3907.91 is the 6-digit subheading for polyesters, n.e.c. in heading no. 3907, unsaturated, in primary forms. It is used for orthophthalic unsaturated polyester resin, isophthalic unsaturated polyester resin, DCPD unsaturated polyester resin, vinyl ester resin and gel coat resins.
What HS 3907.91 covers
This HS code covers unsaturated polyesters in primary forms (resins, pellets) that are not specifically classified elsewhere within heading 3907. These resins are characterized by the presence of carbon-carbon double bonds, enabling them to be cross-linked (cured) into thermoset plastics. They are extensively used as binders in fiberglass reinforced plastics (FRP), for manufacturing composite materials, boat hulls, automotive parts, pipes, tanks, and cultured marble products. Major importers are countries with strong manufacturing bases in construction, automotive, marine, and wind energy sectors, such as China, Germany, and the USA. Exporters include chemical companies from Europe, North America, and Asia. Key aspects of trade involve the demand for lightweight and durable materials, the growth of composite industries, and the specific formulation requirements for various applications, such as orthophthalic, isophthalic, or dicyclopentadiene (DCPD) resins.
- Covers
- Orthophthalic unsaturated polyester resin
- Isophthalic unsaturated polyester resin
- DCPD unsaturated polyester resin
- Vinyl ester resin
- Gel coat resins
- SMC/BMC resins
- Fire retardant unsaturated polyester resin
- Examples
- Ashland Derakane
- Reichhold Polylite
- AOC Aliancys
- Scott Bader Crystic
- BASF Palatal
Codes often confused with 3907.91
Common mistake. These are often confused with saturated polyesters (390799) if the "unsaturated" characteristic is not clearly identified, which is critical for their thermosetting properties. They might also be mistaken for epoxy resins (390730) or other thermosetting resins.
Top exporters and importers of HS code 390791, 2025
In 2025, the largest exporter of HS code 390791 in UN Comtrade data was Italy, with 11% of world exports; the largest importer in UN Comtrade data was Germany, with 8.8% 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 Italy $318M 11% of world exports
- 2 China $308M 11% of world exports
- 3 United States $278M 9.6% of world exports
World total: $2.9B Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 Germany $253M 8.8% of world imports
- 2 Spain $176M 6.1% of world imports
- 3 United States $159M 5.5% of world imports
World total: $2.9B 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 code for 3907.91
Brazil does not split HS 3907.91: its NCM code is 3907.91.00.
All Brazil NCM codes in heading 39.07 →
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text is official; the English is our translation.
Questions about HS 3907.91
What is HS code 390791?
HS code 390791 is a 6-digit subheading in the Harmonized System that covers: Polyesters; n.e.c. in heading no. 3907, unsaturated, in primary forms. This HS code covers unsaturated polyesters in primary forms (resins, pellets) that are not specifically classified elsewhere within heading 3907. These resins are characterized by the presence of carbon-carbon double bonds, enabling them to be cross-linked (cured) into thermoset plastics. They are extensively used as binders in fiberglass reinforced plastics (FRP), for manufacturing composite materials, boat hulls, automotive parts, pipes, tanks, and cultured marble products. Major importers are countries with strong manufacturing bases in construction, automotive, marine, and wind energy sectors, such as China, Germany, and the USA. Exporters include chemical companies from Europe, North America, and Asia. Key aspects of trade involve the demand for lightweight and durable materials, the growth of composite industries, and the specific formulation requirements for various applications, such as orthophthalic, isophthalic, or dicyclopentadiene (DCPD) resins.
What products fall under HS code 390791?
Orthophthalic unsaturated polyester resin, Isophthalic unsaturated polyester resin, DCPD unsaturated polyester resin, Vinyl ester resin, Gel coat resins, SMC/BMC resins, Fire retardant unsaturated polyester resin
What are common misclassifications for HS code 390791?
These are often confused with saturated polyesters (390799) if the "unsaturated" characteristic is not clearly identified, which is critical for their thermosetting properties. They might also be mistaken for epoxy resins (390730) or other thermosetting resins.
Which countries are the top exporters of goods under HS code 390791?
In 2025, the top exporters of HS code 390791 in UN Comtrade data were Italy ($318M, 11% of world exports), China ($308M) and the United States ($278M). World exports came to about $2.9B, 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 390791?
In 2025, the top importers of HS code 390791 in UN Comtrade data were Germany ($253M, 8.8% of world imports), Spain ($176M) and the United States ($159M). World imports came to about $2.9B, 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 390791 structured?
HS code 390791 is a 6-digit subheading under the Harmonized System. The first 2 digits (39) identify the chapter, digits 3-4 (07) identify the heading, and digits 5-6 (91) specify the subheading. This code is standardized globally by the World Customs Organization.
What is the Brazil NCM code for HS code 390791?
In Brazil, HS code 390791 is NCM 3907.91.00. The last two digits are 00 because Brazil does not split this HS code further.