# United States tariff line 2921.51.10.00: 4-Amino-2-(N,N-diethylamino) toluene hydrochloride;m-Phenylenediamine;o-Phenylenediamine; Toluene-2,4-diamine; Toluene-2,5-diamine; and Toluene-2,5-diamine sulfate > In the United States tariff, line 2921.51.10.00 covers aromatic polyamines and their derivatives; salts thereof, o-, m-, p-Phenylenediamine, diaminotoluenes, and their derivatives; salts thereof, 4-Amino-2-(N,N-diethylamino) toluene hydrochloride;m-Phenylenediamine;o-Phenylenediamine; Toluene-2,4-diamine; Toluene-2,5-diamine; and Toluene-2,5-diamine sulfate. The general (MFN) duty rate is 6.5%. It falls under HS subheading 2921.51 in heading 29.21 (chapter 29). Source: https://border.bot/countries/united-states/hs-codes/2921511000 Last updated: 9 October 2026 [Countries](https://border.bot/countries) / [United States](https://border.bot/countries/united-states) / [Chapter 29](https://border.bot/countries/united-states/hs-codes/29) / [2921.51](https://border.bot/countries/united-states/hs-codes/292151) / [2921.51.10.00](https://border.bot/countries/united-states/hs-codes/2921511000) ## Key facts - Tariff line: 2921.51.10.00 - Covers: Aromatic polyamines and their derivatives; salts thereof, o-, m-, p-Phenylenediamine, diaminotoluenes, and their derivatives; salts thereof, 4-Amino-2-(N,N-diethylamino) toluene hydrochloride;m-Phenylenediamine;o-Phenylenediamine; Toluene-2,4-diamine; Toluene-2,5-diamine; and Toluene-2,5-diamine sulfate - Duty (MFN): 6.5% - Preferential rates: From free (17 programmes or origins) - Additional duties: None recorded - Restrictions: None recorded - Tariff: [United States](https://border.bot/countries/united-states) - HS subheading: [2921.51](https://border.bot/hs-codes/292151) ## What this line covers In the United States tariff, line 2921.51.10.00 covers aromatic polyamines and their derivatives; salts thereof, o-, m-, p-Phenylenediamine, diaminotoluenes, and their derivatives; salts thereof, 4-Amino-2-(N,N-diethylamino) toluene hydrochloride;m-Phenylenediamine;o-Phenylenediamine; Toluene-2,4-diamine; Toluene-2,5-diamine; and Toluene-2,5-diamine sulfate. Its legal text is “4-Amino-2-(N,N-diethylamino) toluene hydrochloride;m-Phenylenediamine;o-Phenylenediamine; Toluene-2,4-diamine; Toluene-2,5-diamine; and Toluene-2,5-diamine sulfate”, read under “Aromatic polyamines and their derivatives; salts thereof” and “o-, m-, p-Phenylenediamine, diaminotoluenes, and their derivatives; salts thereof”. Products commonly classified here include m-Phenylenediamine (CAS No. 108-45-2) and 1,3-Benzenediamine (CAS No. 108-45-2) (border.bot’s search keywords, not legal text). ## How it is structured It falls under HS subheading 2921.51 in heading 29.21 (chapter 29). The first six digits are the Harmonized System code; the 4 digits after them are added by the United States tariff. - Chapter 29: Organic chemicals - Heading 29.21: Amine-function compounds - Subheading 2921.51: Aromatic polyamines and their derivatives; salts thereof - Within the subheading: o-, m-, p-Phenylenediamine, diaminotoluenes, and their derivatives; salts thereof - Line 2921.51.10.00: 4-Amino-2-(N,N-diethylamino) toluene hydrochloride;m-Phenylenediamine;o-Phenylenediamine; Toluene-2,4-diamine; Toluene-2,5-diamine; and Toluene-2,5-diamine sulfate ## Duty The general (MFN) duty rate is 6.5%. Duty-free entry applies to goods that qualify under 16 programmes, and to goods from a group of origins (origin group A+). - Free: a group of origins (origin group A+) (A+) - Free: United States-Australia Free Trade Agreement (AU) - Free: United States-Bahrain Free Trade Agreement Implementation Act (BH) - Free: United States-Chile Free Trade Agreement (CL) - Free: United States-Colombia Trade Promotion Agreement Implementation Act (CO) - Free: African Growth and Opportunity Act (D) - Free: Caribbean Basin Economic Recovery Act (E) - Free: United States-Israel Free Trade Area (IL) - Free: United States-Jordan Free Trade Area Implementation Act (JO) - Free: United States-Korea Free Trade Agreement Implementation Act (KR) - Free: United States-Morocco Free Trade Agreement Implementation Act (MA) - Free: United States-Oman Free Trade Agreement Implementation Act (OM) - Free: Dominican Republic-Central America-United States Free Trade Agreement (P) - Free: United States-Panama Trade Promotion Agreement Implementation Act (PA) - Free: United States-Peru Trade Promotion Agreement Implementation Act (PE) - Free: United States-Mexico-Canada Agreement (S) - Free: United States-Singapore Free Trade Agreement (SG) ## In other countries No other national tariff on border.bot has live lines under 2921.51 yet. - [The Harmonized System text for 2921.51](https://border.bot/hs-codes/292151) ## Other lines under 2921.51 - [2921.51.20.00](https://border.bot/countries/united-states/hs-codes/2921512000) Photographic chemicals - [2921.51.30.00](https://border.bot/countries/united-states/hs-codes/2921513000) Products described in additional U.S. note 3 to section VI - [2921.51.50.00](https://border.bot/countries/united-states/hs-codes/2921515000) Other - Previous line: [2921.49.50.00](https://border.bot/countries/united-states/hs-codes/2921495000) Other - Next line: [2921.51.20.00](https://border.bot/countries/united-states/hs-codes/2921512000) Photographic chemicals ## Frequently asked questions ### What does tariff line 2921.51.10.00 cover in the United States tariff? In the United States tariff, line 2921.51.10.00 covers aromatic polyamines and their derivatives; salts thereof, o-, m-, p-Phenylenediamine, diaminotoluenes, and their derivatives; salts thereof, 4-Amino-2-(N,N-diethylamino) toluene hydrochloride;m-Phenylenediamine;o-Phenylenediamine; Toluene-2,4-diamine; Toluene-2,5-diamine; and Toluene-2,5-diamine sulfate. ### What is the general (MFN) duty on 2921.51.10.00 in the United States? The general (MFN) duty rate is 6.5%. ### Which preferential rates apply to 2921.51.10.00? Duty-free entry applies to goods that qualify under 16 programmes: the United States-Australia Free Trade Agreement, the United States-Bahrain Free Trade Agreement Implementation Act, the United States-Chile Free Trade Agreement, the United States-Colombia Trade Promotion Agreement Implementation Act, African Growth and Opportunity Act, Caribbean Basin Economic Recovery Act, the United States-Israel Free Trade Area, the United States-Jordan Free Trade Area Implementation Act, the United States-Korea Free Trade Agreement Implementation Act, the United States-Morocco Free Trade Agreement Implementation Act, the United States-Oman Free Trade Agreement Implementation Act, the Dominican Republic-Central America-United States Free Trade Agreement, the United States-Panama Trade Promotion Agreement Implementation Act, the United States-Peru Trade Promotion Agreement Implementation Act, the United States-Mexico-Canada Agreement and the United States-Singapore Free Trade Agreement, and to goods from a group of origins (origin group A+). ## Sources and updates The tariff lines for the United States come from border.bot release 1 (edition 2026HTSRev21), read from the publisher’s files, and have been live since 9 October 2026. The duty rates for the United States come from border.bot release 1 (edition 2026HTSRev21), read from the publisher’s files, and have been live since 9 October 2026. The trade programmes for the United States come from border.bot release 1 (edition 2026HTSRev21), read from the publisher’s files, and have been live since 9 October 2026. This page was last updated on 9 October 2026. Guidance from published tariff data, not a binding ruling. For a decision customs must follow, apply to the destination’s customs authority for a binding tariff ruling. Official source files: - https://hts.usitc.gov/reststop/exportList?from=0000000000&to=9999999999&format=CSV&styles=false Machine-readable: https://border.bot/countries/united-states/hs-codes/2921511000.json