Polyisobutylene

CN code 390220 covers polyisobutylene (PIB) in primary forms. Polyisobutylene is a polymer obtained by cationic polymerisation of isobutylene (2-methylpropene). Depending on molecular weight, low-molecular-weight polyisobutylene (oligomers, molecular weights from 300 to 2500 Da) is used as a lubricating oil additive, medium-molecular-weight PIB (up to 100,000 Da) serves as a component of adhesives and sealants, and high-molecular-weight PIB (above 100,000 Da) functions as a rheological modifier. PIB is characterised by very low gas permeability, chemical resistance and low-temperature flexibility. Products classified under this code come in the form of granules, blocks, liquids or pastes depending on molecular weight. For customs classification, it is important to distinguish polyisobutylene from butyl rubber, which is classified in Chapter 40.

Polyisobutylene imported into the EU is subject to the REACH Regulation (EC No 1907/2006). Low-molecular-weight PIB may be treated as a chemical substance requiring REACH registration, unlike high-molecular-weight PIB, which meets the definition of a polymer and is exempt from registration. The isobutylene monomer is a flammable substance with CLP classification. For PIB intended for food contact, such as a chewing gum base component or packaging coating, the requirements of Regulation (EU) No 10/2011 and relevant food additive regulations apply. PIB used in pharmaceuticals is subject to additional European Pharmacopoeia requirements. A Safety Data Sheet (SDS) is required for low-molecular-weight forms classified as chemical preparations.

Importing polyisobutylene under CN code 390220 requires technical documentation indicating the molecular weight, viscosity and commercial form of the product. Molecular weight information is important both for tariff classification and REACH regulatory assessment. Duty rates should be verified in the TARIC system for the specific country of origin. Major PIB producers globally include petrochemical companies from Germany, the USA, Japan and China. High-molecular-weight polyisobutylene is transported in blocks or bales on pallets, while low-molecular-weight PIB is shipped as a liquid in drums or tank containers. No specific restrictions apply when exporting PIB from the EU beyond standard customs procedures. Importers should check the availability of tariff preferences under EU trade agreements.

Polyisobutylene classified under CN code 3902 20 are polymers in primary forms (granules, powder, liquid, block) imported as feedstock for plastics processing. Import requires REACH registration, Safety Data Sheets and technical specifications including molecular weight, density and melt flow index (MFI). Products intended for food contact must comply with Regulation (EU) 10/2011 and be listed on the positive monomer list.