Isopropyl Methylphosphonic Acid (IMPA) from Mexico
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 — Mexico → United States
13.7%
Rate breakdown
9903.05.5510%Section 301 (forced labor) — additional 10% ad valorem on products of Mexico
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