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HSN Code 29319011: Methylarsonic acid and its salt

HSN 2931 90 11 is methylarsonic acid and its salt, a tariff item of heading 2931 (other organo-inorganic compounds). GST: 5% / 18%. Basic customs duty: 7.5%. Export policy: Free; RoDTEP 0.7% of FOB value.

Checked against the official files on 2 October 2026Heading 2931Chapter 29 · Organic chemicals
GST rate5% / 18%

More than one entry reaches this code. The description of the goods decides the rate.

Notfn 9/2025-CT (Rate) · 2 entries
Basic customs duty7.5%

Standard rate, unit kg..

Customs Tariff · First Schedule · Ch. 29
Export policyFree

No export authorisation needed.

ITC(HS) 2022 · Schedule 2
RoDTEP0.7%

Of FOB value, exports from the domestic tariff area. AA, SEZ and EOU exports: 0.4%. Up to 31 December 2026.

Appendix 4R · w.e.f. 10 Oct 2024
Classification

Where HSN 2931 90 11 Sits

Use the eight-digit code on the bill of entry, the shipping bill and, where your turnover requires it, on the GST invoice. The first four digits are the heading; the last four narrow it to this line.

Chapter
29 · Organic chemicals
Heading
2931 · Other organo-inorganic compounds
Group
Organo-arsenic compounds
Tariff item
2931 90 11 · Methylarsonic acid and its salt
Unit
kg.
GST

GST Rate on HSN 2931 90 11

GST on goods is fixed by the entries of Notification No. 9/2025-Central Tax (Rate), in force from 22 September 2025 and amended up to 30 April 2026. The entries below are the ones that reach this code. Match the goods to the description in the entry before you invoice.

GST rateEntryCodes namedGoods covered by the entry
5%Schedule I, S. No. 22229 or 3808 93Gibberellic acid (chapter-wide entry)
18%Schedule II, S. No. 3629All organic chemicals other than giberellic acid (chapter-wide entry)
18%Schedule II, S. No. 639Any ChapterGoods which are not specified in Schedule I, III, IV, V, VI or VII (residual entry)

Goods that fall under no specific entry take the residual entry, unless they are exempt under the exemption notification issued with the rate notification.

Import

Customs Duty on HSN 2931 90 11

An import pays basic customs duty at the tariff rate, social welfare surcharge at 10% of that duty (unless exempted for the goods), and IGST at the GST rate on the value plus both duties.

Basic customs duty at
Social welfare surcharge, 10% of the duty
IGST at on value plus both
Total duty and tax
As a share of the value

Standard rates only: no exemption notification, anti-dumping or safeguard duty, or trade-agreement rate is applied, and the surcharge is taken at 10% although some goods are exempted from it. A registered importer takes credit of the IGST.

Export

Export Policy and RoDTEP for HSN 2931 90 11

Schedule 2 of ITC(HS) 2022 marks this tariff item Free. Appendix 4R gives RoDTEP at 0.7% of FOB value for exports from the domestic tariff area and 0.4% for Advance Authorisation, SEZ and EOU exports. The scheme continues up to 31 December 2026.

  1. Current RoDTEP schedule takes effectAppendix 4R and 4RE notified by Notification 32/2024-25.
  2. All rates and caps limited to 50%Notification 60/2025-26, with immediate effect.
  3. Full rates restoredNotification 66/2025-26 and its corrigendum: the rates of 22 February 2026 apply again from 23 March.
  4. Scheme continued to 30 September 2026Notification 74/2025-26, rates unchanged.
  5. Scheme continued to 31 December 2026Notification 41/2026-27: rates and caps as on 30 September 2026 continue.
Same heading

Other Codes Under HSN 2931

Tariff itemDescriptionBasic customs duty
2931 10 10Tetramethyl leadTetramethyl lead and tetraethyl lead7.5%
2931 10 90Tetraethyl leadTetramethyl lead and tetraethyl lead7.5%
2931 20 00Tributyltin compounds7.5%
2931 41 00Dimethyl methylphosphonate7.5%
2931 42 00Dimethyl propylphosphonate7.5%
2931 43 00Diethyl ethylphosphonate7.5%
2931 44 00Methylphosphonic acid7.5%
2931 45 00Salt of methylphosphonic acid and (aminoiminomethyl) urea (1: 1)7.5%
2931 46 002,4,6-Tripropyl-1,3,5,2,4,6-trioxatriphosphinane 2,4,6 -trioxide7.5%
2931 47 00(5-Ethyl-2-methyl-2-oxido-1,3,2-dioxaphosphinan -5-yl) methyl methyl methylphosphonate7.5%
2931 48 003,9-Dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro [5.5] undecane 3,9-dioxide7.5%
2931 49 10Sodium 3-(trihydroxysilyl) propyl methylphosphonateOther7.5%
2931 49 20Bis[(5-ethyl-2-methyl-2-oxido-1,3,2-dioxaphosphinan -5-yl)methyl] methylphosphonate.Other7.5%
2931 49 30Glyphosate (ISO)Other7.5%
2931 49 40Butyl methylphosphinate7.5%
2931 49 50Bis(1-methylpentyl) methylphosphonate7.5%
2931 49 91Containing a phosphorus atom to which one methyl, ethyl, n-propyl or isopropyl group is bonded but no further carbon atoms7.5%
2931 49 99Other7.5%
2931 51 00Methylphosphonic dichloride7.5%
2931 52 00Propylphosphonic dichloride7.5%
2931 53 00O-(3-chloropropyl) O-[4-nitro-3-(trifluoromethyl) phenyl] methylphosphonothionate7.5%
2931 54 00Trichlorfon (ISO)7.5%
2931 59 10P-Alkyl (≤C10, incl. cycloalkyl) N-(1-(dialkyl7.5%
2931 59 20Methyl-(bis(diethylamino)methylene) phosphonamidofluoridate7.5%
2931 59 31Ethephon7.5%
2931 59 39Other7.5%
2931 59 90Other7.5%
2931 90 11Methylarsonic acid and its saltOrgano-arsenic compounds7.5%
2931 90 12Cacodylic acid and its saltOrgano-arsenic compounds7.5%
2931 90 13p-Aminophenylarsonic acid and its saltOrgano-arsenic compounds7.5%
2931 90 14Amino-hydroxyphenylarsonic acids, their formyl and acetyl derivatives and their saltsOrgano-arsenic compounds7.5%
2931 90 15Arsenobenzene and its derivativesOrgano-arsenic compounds7.5%
2931 90 19OtherOrgano-arsenic compounds7.5%
2931 90 20Organo-silicon compoundsOrgano-arsenic compounds7.5%
2931 90 30o-Iodosobenzoic acidOrgano-arsenic compounds7.5%
2931 90 90OtherOrgano-arsenic compounds7.5%
Not shown on this page
  • The item-wise import policy (Free, Restricted or Prohibited) of ITC(HS) Schedule 1.
  • Exemption notifications, anti-dumping and safeguard duties, and preferential rates under trade agreements. The duty shown is the tariff rate.
  • The GST exemption notification. Goods exempt under it pay no GST even if a rate entry names the code.

Official documents behind this page

  1. Notification No. 9/2025-Central Tax (Rate), 17 September 2025GST rate Schedules I to VI, in force from 22 September 2025, as amended by Notification No. 19/2025-Central Tax (Rate) of 31 December 2025 (Schedule VII omitted from 1 February 2026) and No. 01/2026 of 30 April 2026.
  2. Customs Tariff, First ScheduleCBIC Customs Tariff as on 30 June 2024, with the First Schedule amendments of the Finance (No. 2) Act, 2024, the Finance Act, 2025 and the Finance Act, 2026 applied.
  3. ITC(HS) 2022, Schedule 2, Export PolicyDGFT: the export policy and policy condition of each tariff item.
  4. Appendix 4R and Appendix 4RE, RoDTEP ScheduleDGFT, with effect from 10 October 2024 (Notification No. 32/2024-25); the 2026 changes are in Notifications 60, 66 and 74 of 2025-26 and 41 of 2026-27.

Disclaimer: This guide is general information based on the law and notifications in force when it was last updated. It is not professional advice for your case — rates, thresholds and due dates change, so check the current position with the official source before you act on it.

People also ask

Questions, answered

Short, direct answers to the 4 questions readers ask most on this topic.

HSN 2931 90 11 is the tariff item for methylarsonic acid and its salt, under heading 2931 (Other organo-inorganic compounds) of Chapter 29.

The entries of Notification No. 9/2025-Central Tax (Rate) that reach this code give 5% / 18%. The rate depends on the description in the entry.

The basic customs duty in the Customs Tariff is 7.5%. Social welfare surcharge at 10% of the duty and IGST at the GST rate are added. An exemption notification or a trade agreement can reduce the duty actually payable.

Yes. Appendix 4R lists the code at 0.7% of FOB value. The scheme continues up to 31 December 2026.