HS Code for Butyl rubber

Butyl rubber, scientifically designated as isobutene-isoprene rubber (IIR), is a synthetic elastomer renowned for its unique properties. Its classification under HS code 4002.31 is highly specific and accurate, as this subheading explicitly identifies "isobutene-isoprene (butyl) rubber (IIR)" within the broader category of "Synthetic rubber and factice derived from oils, in primary forms or in plates, sheets or strip" (4002). This precise description directly corresponds to the chemical composition and common industrial nomenclature of butyl rubber, which is a copolymer of isobutylene with a small percentage of isoprene. The code encompasses the material in its initial, unprocessed forms, such as bales, crumbs, or sheets, prior to its conversion into finished articles. Its classification within Chapter 40, which covers rubber and articles thereof, is based on its polymeric nature and its role as a raw material in the rubber industry.

Products Included

• Isobutene-isoprene rubber (IIR)
• Halogenated butyl rubber (e.g., chlorobutyl rubber, bromobutyl rubber), provided they are in primary forms or plates, sheets, or strip.
• Butyl rubber crumbs
• Butyl rubber bales

Common Misclassification

Misclassification of butyl rubber can occur if its specific chemical structure is not carefully considered. HS 4002.19, which covers "Other styrene-butadiene rubber (SBR) (other than latex)", is a common point of confusion, as both are synthetic rubbers. However, SBR is derived from styrene and butadiene monomers, fundamentally different from the isobutene-isoprene monomers of butyl rubber. Similarly, HS 4002.20 for "Butadiene rubber (BR)" is distinct, as BR is a homopolymer of butadiene. The explicit mention of "isobutene-isoprene (butyl) rubber (IIR)" in 4002.31 is crucial for accurate differentiation. Furthermore, if butyl rubber has been compounded with fillers or other additives but not yet vulcanized, it might be mistakenly classified under HS 4005, "Compounded rubber, unvulcanised, in primary forms or in plates, sheets or strip". However, 4002.31 is reserved for the pure synthetic rubber in its primary forms, before significant compounding.

FAQ

What is the HS code for Butyl rubber?

The HS code for Butyl rubber is 4002.31.

What are the key properties of Butyl rubber?

Butyl rubber is known for its excellent impermeability to gases, good resistance to heat, ozone, and chemicals, and high damping properties, making it suitable for inner tubes, seals, and pharmaceutical stoppers.