2931.48.00.00/Antioxidant 552 (3,9-Dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide)/Japan

Antioxidant 552 (3,9-Dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide) from Japan

Antioxidant 552 is the commercial grade of 3,9-dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, a non-halogenated organo-phosphorus stabilizer for polymers. It falls under HTS 2931.48.00.00 due to its specific spiro phosphonate structure with P-C bonds, as defined in Chapter 29 heading 2931.

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%

Calculate with your customs value Verify classification with AI

Import Tips

• Label with commercial name and CAS number (CAS 65481-32-7) for easy verification

• Test for stabilizer additives to ensure they qualify under Chapter 29 note (f) without changing classification

• Avoid bulk mixtures to prevent reclassification as preparations