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Isopropyl Methylphosphonic Acid (IMPA) from Japan

IMPA contains a phosphorus atom bonded to one methyl group and one isopropoxy group (P-CH3, P-O-CH(CH3)2). Fits HTS 2931.49.0055 as the phosphorus has one isopropyl group allowed by the heading description with no further carbon atoms in the chain. Marker compound for chemical weapons verification.

Duty Rate — Japan → United States

12.5%

Rate breakdown

9903.05.4912.5%Section 301 (forced labor) — Japan (col1 rate < 12.5 percent): MFN < 12.5% → total duty capped at 12.5%

Import Tips

Include OPCW or laboratory certification for legitimate analytical use to avoid security delays

Test for impurities that could trigger reclassification to pesticide headings (3808)

Store and ship as corrosive solid; verify temperature control for stability