Product classification
HS code for PIB: 3902.20
Propylene, other olefin polymers, polyisobutylene in primary forms.
Classification of PIB under HS 3902.20
Polyisobutylene (PIB) is classified under HS code 3902.20, which falls under the category of polymers of propylene or other olefins in primary forms. Chapter 39 of the Harmonized System deals with plastics and articles thereof, and heading 3902 is dedicated to polymers of propylene or other olefins. Subheading 3902.20 specifically identifies polyisobutylene. The classification is determined by the chemical structure of the polymer, which is a synthetic rubber or semi-solid viscous polymer. For the purposes of this classification, "primary forms" are defined in Note 6 to Chapter 39 as liquids and pastes, including dispersions (emulsions and suspensions) and solutions, or blocks of irregular shape, lumps, powders, granules, flakes, and similar bulk forms. PIB is valued for its impermeability to gases and its flexibility. It is used extensively in the manufacture of inner tubes, adhesives, and as a viscosity modifier in lubricant oils. The classification process involves verifying that the substance is a polymer where isobutylene monomer units predominate by weight over any other single comonomer unit, in accordance with the polymer notes in Chapter 39. If the product is mixed with other substances, such as solvents or additives, it must still retain the character of a polymer in primary form to remain under this code.
- Covers
- Low molecular weight polyisobutylene in liquid form
- High molecular weight PIB in solid blocks
- Polyisobutylene granules for industrial use
- PIB dispersions used in adhesive manufacturing
- Also under 3902.20
- BASF Oppanol
- ExxonMobil Vistanex
- Lanxess Krynac
- TPC Polybutene
- INEOS Oronite
Codes often confused with 3902.20
Common mistake. PIB is frequently misclassified under 3901.10 or 3901.20 (Polyethylene) due to its similar appearance in pellet form. It may also be confused with 4002.31 (Butyl rubber), which is a copolymer of isobutylene and isoprene; pure PIB must be classified in Chapter 39, while the copolymer is classified in Chapter 40. Additionally, if PIB is heavily diluted in mineral oil (less than 50% polymer), it might be misclassified under 2710.19 as a lubricant additive.
Top exporters and importers of HS 390220 (the code used for PIB), 2025
In 2025, the largest exporter of HS 390220 (the code used for PIB) in UN Comtrade data was South Korea, with 28% of world exports; the largest importer in UN Comtrade data was China, with 19% 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 390220, not only PIB.
Top exporters 2025 · share of world exports
- 1 South Korea $329M 28% of world exports
- 2 United States $158M 14% of world exports
- 3 Belgium $156M 13% of world exports
World total: $1.2B Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 China $226M 19% of world imports
- 2 France $148M 13% of world imports
- 3 Singapore $130M 11% of world imports
World total: $1.2B 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 PIB
Brazil classifies PIB under NCM 3902.20.00: HS 3902.20 with 00 added.
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.
Questions about PIB
What is the HS code for PIB?
The HS code for PIB is 390220 (Propylene, other olefin polymers; polyisobutylene in primary forms). The HS code for Polyisobutylene in primary forms is 3902.20.
How do I classify PIB for customs?
PIB is classified under HS code 390220 — Propylene, other olefin polymers; polyisobutylene in primary forms. This is a 6-digit subheading level code.
Is PIB classified as a plastic or a rubber?
In the Harmonized System, pure polyisobutylene is classified as a plastic under Chapter 39 (3902.20), whereas its copolymer, butyl rubber, is classified as synthetic rubber under Chapter 40.
Which countries are the top exporters of PIB (HS 390220)?
In 2025, the top exporters of HS 390220 (the code used for PIB) in UN Comtrade data were South Korea ($329M, 28% of world exports), the United States ($158M) and Belgium ($156M). World exports came to about $1.2B, 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 PIB (HS 390220)?
In 2025, the top importers of HS 390220 (the code used for PIB) in UN Comtrade data were China ($226M, 19% of world imports), France ($148M) and Singapore ($130M). World imports came to about $1.2B, 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 PIB the same in all countries?
The base HS code 390220 for PIB 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 PIB in Brazil?
In Brazil, PIB (HS 390220) is classified under NCM 3902.20.00.