1,6-Hexamethylene Diisocyanate (HDI)
1,6-Hexamethylene diisocyanate (HDI) is a chemically defined aliphatic diisocyanate with the formula OCNC6H12NCO, used primarily as a reactive intermediate in polyurethane production. It falls under HTS 2929.10.3500 as an isocyanate compound with other nitrogen function, specifically named in the tariff schedule. This clear, colorless liquid is essential for creating durable coatings and adhesives.
Import Duty Rates by Country of Origin
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If imported as a mixture with >2 isomers or impurities exceeding tolerance
Chapter note (b) directs mixtures of isomers to potentially different subheadings within 2929.10, but pure HDI stays at .3500
If pre-mixed as polyurethane prepolymer for specific end-use rather than pure intermediate
Solutions or mixtures exceeding Chapter 29 scope (note e) shift to Chapter 38 as chemical preparations, not pure compounds
If reacted into peptide linkages as polyurethane prepolymer resembling synthetic polypeptide
If HDI is no longer a separate diisocyanate but part of a larger polymer chain, it may classify under synthetic peptides
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Import Tips & Compliance
• Obtain proper SDS (Safety Data Sheets) and ensure packaging meets UN standards for hazardous materials transport (Class 6.1 toxic liquid)
• Verify importer security filing (ISF) includes accurate chemical composition to avoid CBP holds; include stabilizer declarations if present
Related Products under HTS 2929.10.35.00
HDI Biuret Trimer (Desmodur N 100)
HDI Biuret trimer is a high-functionality polyisocyanate derived from 1,6-hexamethylene diisocyanate, containing residual monomeric HDI (<0.25%). It qualifies under HTS 2929.10.3500 as an isocyanate per Chapter notes allowing derivatives of listed compounds. Primarily used as crosslinking agent in durable industrial coatings.
Desmodur H Diisocyanate
Desmodur H is the commercial trade name for high-purity 1,6-hexamethylene diisocyanate (HDI) produced by Covestro, stabilized with <0.1% benzoyl chloride for transport. Classed under HTS 2929.10.3500 as the specifically named isocyanate per Chapter 29 notes (f) allowing stabilizers. Used in two-component polyurethane paints for automotive clearcoats.
Monodisperse HDI (Purified 99.5%)
Laboratory-grade 1,6-hexamethylene diisocyanate with 99.5% purity, minimal isomeric impurities, packaged in 1-5kg quantities for R&D. Falls squarely under HTS 2929.10.3500 as chemically defined isocyanate per Chapter note (a). Used in synthesis of biomedical polyurethanes and adhesives.
HDI Stabilized with 0.02% HDB Catapult
Industrial 1,6-hexamethylene diisocyanate stabilized with proprietary 0.02% HDB Catapult additive to prevent yellowing during storage. HTS 2929.10.3500 applies per Chapter note (f) for added stabilizers necessary for transport. Standard for non-yellowing wood floor coatings.