# HS code 8506.40: Silver oxide

> HS code 8506.40 covers silver oxide. It sits in heading 85.06 (primary cells and primary batteries) in chapter 85 (electrical machinery and equipment and parts thereof; sound recorders and reproducers, television image and sound recorders and reproducers, and parts and accessories of such articles). Other goods of heading 85.06 are classified under 8506.10 (manganese dioxide), 8506.30 (mercuric oxide), 8506.50 (lithium), 8506.60 (air-zinc) or 2 others. National tariff lines under 8506.40 are live on border.bot for the United States (3 lines, also used by 1 other country).

Source: https://border.bot/hs-codes/850640
Last updated: 11 October 2026

[HS codes](https://border.bot/hs-codes) / [Chapter 85](https://border.bot/hs-codes/85) / [85.06](https://border.bot/hs-codes/8506) / [8506.40](https://border.bot/hs-codes/850640)

## Key facts

- HS code: 8506.40
- Covers: Silver oxide
- Heading: [85.06: Primary cells and primary batteries](https://border.bot/hs-codes/8506)
- Chapter: [85: Electrical machinery and equipment and parts thereof; sound recorders and reproducers, television image and sound recorders and reproducers, and parts and accessories of such articles](https://border.bot/hs-codes/85)
- Edition: HS2022
- Duty in the United States: [See its 3 lines](https://border.bot/countries/united-states/hs-codes/850640)

## What this code covers

HS code 8506.40 covers silver oxide.

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

## What it doesn’t cover

Other goods of heading 85.06 are classified under 8506.10 (manganese dioxide), 8506.30 (mercuric oxide), 8506.50 (lithium), 8506.60 (air-zinc) or 2 others.

- [8506.10](https://border.bot/hs-codes/850610) Manganese dioxide
- [8506.30](https://border.bot/hs-codes/850630) Mercuric oxide
- [8506.50](https://border.bot/hs-codes/850650) Lithium
- [8506.60](https://border.bot/hs-codes/850660) Air-zinc
- [8506.80](https://border.bot/hs-codes/850680) Other primary cells and primary batteries
- [8506.90](https://border.bot/hs-codes/850690) Parts

## How it is structured

8506.40 is a six-digit subheading. Its first two digits, 85, are the chapter; the first four, 8506, are heading 85.06; the last two, 40, identify the subheading within the heading.

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

- Chapter 85: Electrical machinery and equipment and parts thereof; sound recorders and reproducers, television image and sound recorders and reproducers, and parts and accessories of such articles
- Heading 85.06: Primary cells and primary batteries
- Subheading 8506.40: Silver oxide

## In other countries

National tariff lines under 8506.40 are live on border.bot for the United States (3 lines, also used by 1 other country).

- [United States](https://border.bot/countries/united-states/hs-codes/850640): 3 lines, used by 1 other country

- Previous subheading: [8506.30](https://border.bot/hs-codes/850630) Mercuric oxide
- Next subheading: [8506.50](https://border.bot/hs-codes/850650) Lithium

## Frequently asked questions

### What does HS code 8506.40 cover?

HS code 8506.40 covers silver oxide.

### Which heading and chapter is HS code 8506.40 in?

HS code 8506.40 is in heading 85.06 (primary cells and primary batteries) in chapter 85 (electrical machinery and equipment and parts thereof; sound recorders and reproducers, television image and sound recorders and reproducers, and parts and accessories of such articles).

### Where are goods of heading 85.06 classified when 8506.40 doesn’t fit?

Other goods of heading 85.06 are classified under 8506.10 (manganese dioxide), 8506.30 (mercuric oxide), 8506.50 (lithium), 8506.60 (air-zinc) or 2 others.

### Which countries’ tariffs list national lines under HS code 8506.40?

National tariff lines under 8506.40 are live on border.bot for the United States (3 lines, also used by 1 other country).

## Sources and updates

The Harmonized System legal text comes from border.bot release 2 (edition HS 2022), imported from a file, and has been live since 11 October 2026.

This page was last updated on 11 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://border.bot/hs-codes/850640.json