# HS code 2831.90: Dithionites and sulphoxylates

> HS code 2831.90 covers dithionites and sulphoxylates, other than those classified in 2831.10. It sits in heading 28.31 (dithionites and sulphoxylates) in chapter 28 (inorganic chemicals; organic or inorganic compounds of precious metals, of rare-earth metals, of radioactive elements or of isotopes). Other goods of heading 28.31 are classified under 2831.10 (of sodium).

Source: https://staging.border.bot/hs-codes/283190
Last updated: 13 October 2026

[HS codes](https://staging.border.bot/hs-codes) / [Chapter 28](https://staging.border.bot/hs-codes/28) / [28.31](https://staging.border.bot/hs-codes/2831) / [2831.90](https://staging.border.bot/hs-codes/283190)

## Key facts

- HS code: 2831.90
- Covers: Dithionites and sulphoxylates
- Heading: [28.31: Dithionites and sulphoxylates](https://staging.border.bot/hs-codes/2831)
- Chapter: [28: Inorganic chemicals; organic or inorganic compounds of precious metals, of rare-earth metals, of radioactive elements or of isotopes](https://staging.border.bot/hs-codes/28)
- Edition: HS2022
- Duty rates: [Set by each country’s tariff](https://staging.border.bot/countries)

## What this code covers

HS code 2831.90 covers dithionites and sulphoxylates, other than those classified in 2831.10.

The legal text of the subheading is “Other”, in HS2022.

## What it doesn’t cover

Other goods of heading 28.31 are classified under 2831.10 (of sodium).

- [2831.10](https://staging.border.bot/hs-codes/283110) Of sodium

## How it is structured

2831.90 is a six-digit subheading. Its first two digits, 28, are the chapter; the first four, 2831, are heading 28.31; the last two, 90, identify the subheading within the heading.

Countries add their own digits after these six for their national tariff lines.

- Chapter 28: Inorganic chemicals; organic or inorganic compounds of precious metals, of rare-earth metals, of radioactive elements or of isotopes
- Heading 28.31: Dithionites and sulphoxylates
- Subheading 2831.90: Other

## In other countries

No national tariff lines under 2831.90 are live on border.bot yet. Tariffs built on the Harmonized System (HS2022) use 2831.90 at six digits and add their own digits after it.

- Previous subheading: [2831.10](https://staging.border.bot/hs-codes/283110) Of sodium
- Next subheading: [2832.10](https://staging.border.bot/hs-codes/283210) Sodium sulphites

## Frequently asked questions

### What does HS code 2831.90 cover?

HS code 2831.90 covers dithionites and sulphoxylates, other than those classified in 2831.10.

### Which heading and chapter is HS code 2831.90 in?

HS code 2831.90 is in heading 28.31 (dithionites and sulphoxylates) in chapter 28 (inorganic chemicals; organic or inorganic compounds of precious metals, of rare-earth metals, of radioactive elements or of isotopes).

### Where are goods of heading 28.31 classified when 2831.90 doesn’t fit?

Other goods of heading 28.31 are classified under 2831.10 (of sodium).

## Sources and updates

The Harmonized System legal text comes from border.bot release 1 (edition HS 2022), imported from a file, and has been live since 13 October 2026.

This page was last updated on 13 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.

Machine-readable: https://staging.border.bot/hs-codes/283190.json