Schedule in force 2026-08-31HTS 2026HTSRev17HTS 2931 · Chapter 29
Tariff Watch
For business

HTS 2931

Heading 2931 covers other organo-inorganic compounds. Duty is assessed at the 10-digit statistical line; the figures here are resolved for 2931.10.00.00, the first line under this heading. Its Column 1 rate is 3.7%; other lines under 2931 carry different Column 1 rates. On top of that, the ad valorem total depends on origin: China carries 41.20% and Italy carries 10.00%.

Chapter 29 · Verified 2026-08-31
HTS 2026HTSRev17

46 statistical lines under this heading · 4 distinct Column 1 rates · highest ad valorem total 41.20% from China · lowest 10.00% from Italy

OriginAd valorem layersLayersReported under
China CHN41.20%mfn + s301 + s3019903.88.03 9903.05.31
Vietnam VNM16.20%mfn + s3019903.05.84
Thailand THA16.20%mfn + s3019903.05.77
Brazil BRA16.20%mfn + s3019903.05.27
Mexico MEX13.70%mfn + s3019903.05.55
Canada CAN13.70%mfn + s3019903.05.29
India IND13.70%mfn + s3019903.05.44
United Kingdom GBR13.70%mfn + s3019903.05.81
Japan JPN12.50%s3019903.05.49
South Korea KOR12.50%s3019903.05.71
Germany DEU10.00%s3019903.05.39
Italy ITA10.00%s3019903.05.39
Table 1Rate by country of origin for 2931.10.00.00, resolved 2026-08-31. The first statistical line under 2931; other lines may carry different Column 1 rates.
CodeDescriptionColumn 1SpecialUnits
2931.10.00.00Tetramethyl lead and tetraethyl lead3.7%Free (A,AU,BH,CL,CO,D,E,IL,JO,KR,MA,OM,P,PA,PE,S,SG)kg
2931.20.00.00Tributyltin compounds3.7%Free (A,AU,BH,CL,CO,D,E,IL,JO,KR,MA,OM,P,PA,PE,S,SG)kg
2931.41.00.00Dimethyl methylphosphonate3.7%Free (A,AU,BH,CL,CO,D,E,IL,JO,K,KR,MA,OM,P,PA,PE,S,SG)kg
2931.42.00.00Dimethyl propylphosphonate3.7%Free (A,AU,BH,CL,CO,D,E,IL,JO,K,KR,MA,OM,P,PA,PE,S,SG)kg
2931.43.00.00Diethyl ethylphosphonate3.7%Free (A,AU,BH,CL,CO,D,E,IL,JO,K,KR,MA,OM,P,PA,PE,S,SG)kg
2931.44.00.00Methylphosphonic acid3.7%Free (A,AU,BH,CL,CO,D,E,IL,JO,K,KR,MA,OM,P,PA,PE,S,SG)kg
2931.45.00.00Salt of methylphosphonic acid and (aminoiminomethyl)urea (1:1)3.7%Free (A,AU,BH,CL,CO,D,E,IL,JO,K,KR,MA,OM,P,PA,PE,S,SG)kg
2931.46.00.002,4,6-Tripropyl-1,3,5,2,4,6-trioxatriphosphinane 2,4,6-trioxide3.7%Free (A,AU,BH,CL,CO,D,E,IL,JO,K,KR,MA,OM,P,PA,PE,S,SG)kg
2931.47.00.00(5-Ethyl-2-methyl-2-oxido-1,3,2-dioxaphosphinan-5-yl) methyl methyl methylphosphonate3.7%Free (A,AU,BH,CL,CO,D,E,IL,JO,K,KR,MA,OM,P,PA,PE,S,SG)kg
2931.48.00.003,9-Dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro [5.5] undecane 3,9-dioxide3.7%Free (A,AU,BH,CL,CO,D,E,IL,JO,K,KR,MA,OM,P,PA,PE,S,SG)kg
2931.49.00.05O-Alkyl (≤C10, including cycloalkyl) N,N-dialkyl (methyl, ethyl, n-propyl or isopropyl) phosphoramidocyanidatesinherited—kg
2931.49.00.08[O-2-(Dialkyl (methyl, ethyl, n-propyl or isopropyl) amino)ethyl] hydrogen alkyl (methyl, ethyl, n-propyl or isopropyl) phosphonites and their O-alkyl (≤C10, including cycloalkyl) esters; alkylated or protonated salts thereofinherited—kg
2931.49.00.102-Amino-4-[hydroxy(methyl)phosphonoyl] butanoic acid (glufosinate) and its salts and estersinherited—kg
2931.49.00.15Butyl methylphosphinateinherited—kg
2931.49.00.20N-(Phosphonomethyl) glycine (glyphosate) and its salts and estersinherited—kg
2931.49.00.25Bis(1-methylpentyl) methylphosphonateinherited—kg
2931.49.00.55Containing a phosphorus atom to which one methyl, ethyl, n-propyl or isopropyl group is bonded but no further carbon atomsinherited—kg
2931.49.00.80Otherinherited—kg
2931.51.00.00Methylphosphonic dichloride3.7%Free (A,AU,BH,CL,CO,D,E,IL,JO,K,KR,MA,OM,P,PA,PE,S,SG)kg
2931.52.00.00Propylphosphonic dichloride3.7%Free (A,AU,BH,CL,CO,D,E,IL,JO,K,KR,MA,OM,P,PA,PE,S,SG)kg
2931.53.00.00O-(3-chloropropyl) O-[4-nitro-3-(trifluoromethyl)phenyl] methylphosphonothionate3.7%Free (A,AU,BH,CL,CO,D,E,IL,JO,K,KR,MA,OM,P,PA,PE,S,SG)kg
2931.54.00.00Trichlorfon (ISO)3.7%Free (A,AU,BH,CL,CO,D,E,IL,JO,K,KR,MA,OM,P,PA,PE,S,SG)kg
2931.59.00.10O-Alkyl (≤ C10, including cycloalkyl) alkyl (methyl, ethyl,n- propyl or isopropyl) phosphonofluoridatesinherited—kg
2931.59.00.15Alkyl (methyl, ethyl, n-propyl or isopropyl) phosphonyl difluoridesinherited—kg
2931.59.00.20O-Isopropyl methylphosphonochloridateinherited—kg
2931.59.00.25O-Pinacolyl methylphosphonochloridateinherited—kg
2931.59.00.30P-Alkyl (≤ C10, incl. cycloalkyl) N-(1-(dialkyl (≤ C10, incl. cycloalkyl) amino))alkylidene (H or ≤C10, incl. cycloalkyl) phosphonamidic fluorides and corresponding alkylated or protonated saltsinherited—kg
2931.59.00.35Methyl- bis(diethylamino)methylene)phosphonamidofluoridateinherited—kg
2931.59.00.60Containing a phosphorus atom to which one methyl, ethyl, n-propyl or isopropyl group is bonded but no further carbon atomsinherited—kg
2931.59.00.80Otherinherited—kg
2931.90.05.00Diphenyldichlorosilane; and phenyltrichlorosilaneFree—kg
2931.90.10.004,4'-Diphenylbisphosphonous acid, di(2',2",4',4"-di-tert-butyl)phenyl ester6.5%Free (A+, AU, BH, CL,CO,D, E, IL, JO, KR, MA, OM, P, PA, PE, S, SG)kg
2931.90.15.00Sodium tetraphenylboron5.8%Free (A+, AU, BH, CL, CO, D, E, IL, JO, KR, MA, OM, P, PA, PE, S, SG)kg
2931.90.22.00Drugs6.5%Free (A+,AU,BH,CL,CO,D, E,IL,JO,K, KR,MA,OM,P, PA,PE,S,SG)kg
2931.90.26.00Pesticides6.5%Free (A*,AU,BH,CL,CO,D,E,IL,JO,KR,MA,OM,P,PA,PE,S,SG)kg
2931.90.30.00Products described in additional U.S. note 3 to section VI6.5%Free (A+,AU,BH,CL,CO,D, E,IL,JO,K, KR,MA,OM,P, PA,PE,S,SG)kg
2931.90.60.00Other6.5%Free (A+,AU,BH,CL,CO,D, E,IL,JO,K, KR,MA,OM,P, PA,PE,S,SG)kg
2931.90.70.00N,N'-Bis(trimethylsilyl) urea; 3-(Hydroxymethylphosphinyl)-1-propanoic acid, 2-hydroxyethyl ester; and 2-Phosphonobutane-1,2,4-tricarboxylic acid and its saltsFree—kg
2931.90.90.10Organo-silicon compoundsinherited—kg
2931.90.90.21Dibutyltin oxideinherited—kg
2931.90.90.25Tetrabutyltininherited—kg
2931.90.90.29Otherinherited—kg
2931.90.90.302-Chlorovinyldichloroarsineinherited—kg
2931.90.90.35Bis(2-chlorovinyl)chloroarsineinherited—kg
2931.90.90.40Tris(2-chlorovinyl)arsineinherited—kg
2931.90.90.52Otherinherited—kg
Table 2Statistical suffixes under 2931. Duty is assessed at the 10-digit level; the Column 1 rate is stated at the subheading and inherited below it.
ProgrammeRate as publishedContributionReported underIn force from
Column 1 General (MFN)3.7%3.70%—not established

Source: USITC, Harmonized Tariff Schedule of the United States, 2026 HTS Revision 17, published 2026-08-01. Verified 2026-08-31.

Section 301The duty provided in the applicable subheading + 25%25.00%9903.88.032018-09-24
Status unconfirmed. The second statutory four-year review of this action is running. The continuation-request deadlines for the underlying 2018 actions closed on 2026-07-05 and 2026-08-22 and no continuation notice has been published. There is no evidence of termination either, and the duty is almost certainly still collectible; what we cannot do is cite a document saying so.

Source: USTR, Notice of Modification of Section 301 Action: China's Acts, Policies and Practices Related to Technology Transfer (List 3) (83 FR 47974), published 2018-09-21. Verified 2026-08-31.

Section 301The duty provided in the applicable subheading + 12.5%12.50%9903.05.312026-07-24

Source: USTR, Notice of Actions in Section 301 Investigations of Various Economies (FR Doc. 2026-15181), published 2026-07-28. Verified 2026-08-31.

Table 3Duty stack for 2931.10.00.00 from China, resolved 2026-08-31.

Common questions

What is the duty rate for HTS 2931?
Heading 2931 covers other organo-inorganic compounds. Duty is assessed at the 10-digit statistical line; the figures here are resolved for 2931.10.00.00, the first line under this heading. Its Column 1 rate is 3.7%; other lines under 2931 carry different Column 1 rates. On top of that, the ad valorem total depends on origin: China carries 41.20% and Italy carries 10.00%.
Why does the rate differ by country for the same HTS code?
The Column 1 rate is the same for every origin with normal trade relations. Trade-remedy duties under Sections 232, 301 and 338 are imposed by origin, by product, or by both, so two shipments of the same article from different countries can carry very different totals.
Is this the rate I will actually pay?
It is the rate that applies to this classification and origin on the date shown. The duty owed on a specific entry also depends on the 10-digit statistical suffix, declared content where a duty is content-based, preference eligibility, and any AD/CVD order in scope.