Brazil NCM · 8-digit subitem

NCM 2931.90.51 – Methylarsinic acid and its salts

NCM 2931.90.51 (also written 29319051) is Brazil's code for methylarsinic acid and its salts. Its first 6 digits are HS code 2931.90.

Official description of NCM 2931.90.51

PortuguêsOfficial
Ácido metilarsínico e seus sais
EnglishUnofficial translation

Methylarsinic acid and its salts

Nomenclatura Comum do Mercosul (Siscomex). Updated Oct 2026 · In force since Apr 2022 (Res Gecex 272/2021).

How to read NCM 2931.90.51

29Chapter 31Heading 90Subheading

HS code 2931.90
Same in every country

5Item 1Subitem

Added by Mercosur
Brazil, Argentina, Paraguay, Uruguay

The first 6 digits are the international HS code, so their meaning is the same in every country; Brazil publishes the text in Portuguese. Digits 7 and 8 are Brazil's own split of that HS code. The full 8-digit code is used on import declarations (DUIMP), invoices (NF-e) and tax filings.

Full classification path

  1. Chapter 29 Organic chemicals Produtos químicos orgânicos.
  2. Heading 29.31 Other organo-inorganic compounds Outros compostos organo-inorgânicos.
  3. Subheading 2931.90 Organo-inorganic compounds; other than tetramethyl lead, tetraethyl lead, tributyltin compounds, and other organo-phosphorous derivatives Outros
  4. Item 2931.90.5 Organo-arsenic compounds Compostos organoarseniais
  5. Subitem 2931.90.51 Methylarsinic acid and its salts Ácido metilarsínico e seus sais

Other NCM codes under HS 2931.90

2931.90.21 Bis(trimethylsilyl)ureaBis(trimetilsilil)ureia 2931.90.29 Other organosilicon compoundsOutros 2931.90.41 Triphenyltin acetateAcetato de trifenilestanho 2931.90.42 TetraoctyltinTetraoctilestanho 2931.90.43 CyhexatinCiexatin 2931.90.44 Triphenyltin hydroxideHidróxido de trifenilestanho 2931.90.45 Fenbutatin oxideÓxido de fembutatina 2931.90.46 Dialkyltin (C1/C4/C8) carboxylates, thioglycolatesSais de dimetil-estanho, de dibutil-estanho e de dioctil-estanho, dos ácidos carboxílicos ou tioglicólicos e de seus ésteres 2931.90.49 Other organotin compoundsOutros 2931.90.52 2-Chlorovinyldichloroarsine (lewisite 1)2-Clorovinil-dicloroarsina 2931.90.53 Bis(2-chlorovinyl)chloroarsine (lewisite 2)Bis(2-clorovinil)cloroarsina 2931.90.54 Tris(2-chlorovinyl)arsine (lewisite 3)Tris(2-clorovinil)arsina 2931.90.59 Other organo-arsenic compoundsOutros 2931.90.61 Ethylaluminium sesquichlorideTricloreto de etilalumínio (sesquicloreto de etilalumínio) 2931.90.62 Diethylaluminium chlorideCloreto de dietilalumínio 2931.90.69 Other organo-aluminium compoundsOutros 2931.90.90 Other organo-inorganic compounds not specifiedOutros

Questions about NCM 2931.90.51

What is NCM 2931.90.51?

NCM 2931.90.51 (29319051) is the Brazilian (Mercosur) code for methylarsinic acid and its salts. Its official Portuguese description is “Ácido metilarsínico e seus sais”.

What is the HS code for NCM 2931.90.51?

HS 2931.90 (Organo-inorganic compounds; other than tetramethyl lead, tetraethyl lead, tributyltin compounds, and other organo-phosphorous derivatives). The first 6 digits of an NCM code are its international HS code; the last 2 digits are Brazil's own split.

Is an NCM code the same as an HS code?

The first 6 digits are the same in every country. NCM adds an item digit (7th) and a subitem digit (8th). A code ending in 00 means Brazil does not split that HS code further.

Which countries use NCM 2931.90.51?

All Mercosur members use the same NCM codes: Argentina, Brazil, Paraguay and Uruguay.

Source: Siscomex Classif NCM table, updated Oct 2026 (Resolução Gecex nº 926/2026). The Portuguese text is the official one; the English is our translation.