# HS code 3811.90: Anti-knock preparations, oxidation inhibitors, gum inhibitors, viscosity improvers, anti-corrosive preparations and other prepared additives, for mineral oils (including gasoline) or for other liquids used for the same purposes as mineral oils

> HS code 3811.90 covers anti-knock preparations, oxidation inhibitors, gum inhibitors, viscosity improvers, anti-corrosive preparations and other prepared additives, for mineral oils (including gasoline) or for other liquids used for the same purposes as mineral oils, other than those classified in 3811.11, 3811.19, 3811.21 and 3811.29. It sits in heading 38.11 (anti-knock preparations, oxidation inhibitors, gum inhibitors, viscosity improvers, anti-corrosive preparations and other prepared additives, for mineral oils (including gasoline) or for other liquids used for the same purposes as mineral oils) in chapter 38 (miscellaneous chemical products). Other goods of heading 38.11 are classified under 3811.11 (anti-knock preparations, based on lead compounds), 3811.19 (anti-knock preparations, other), 3811.21 (additives for lubricating oils, containing petroleum oils or oils obtained from bituminous minerals) and 3811.29 (additives for lubricating oils, other). National tariff lines under 3811.90 are live on border.bot for the United States (1 line, also used by 1 other country).

Source: https://border.bot/hs-codes/381190
Last updated: 11 October 2026

[HS codes](https://border.bot/hs-codes) / [Chapter 38](https://border.bot/hs-codes/38) / [38.11](https://border.bot/hs-codes/3811) / [3811.90](https://border.bot/hs-codes/381190)

## Key facts

- HS code: 3811.90
- Covers: Anti-knock preparations, oxidation inhibitors, gum inhibitors, viscosity improvers, anti-corrosive preparations and other prepared additives, for mineral oils (including gasoline) or for other liquids used for the same purposes as mineral oils
- Heading: [38.11: Anti-knock preparations, oxidation inhibitors, gum inhibitors, viscosity improvers, anti-corrosive preparations and other prepared additives, for mineral oils (including gasoline) or for other liquids used for the same purposes as mineral oils](https://border.bot/hs-codes/3811)
- Chapter: [38: Miscellaneous chemical products](https://border.bot/hs-codes/38)
- Edition: HS2022
- Duty in the United States: [See its 1 line](https://border.bot/countries/united-states/hs-codes/381190)

## What this code covers

HS code 3811.90 covers anti-knock preparations, oxidation inhibitors, gum inhibitors, viscosity improvers, anti-corrosive preparations and other prepared additives, for mineral oils (including gasoline) or for other liquids used for the same purposes as mineral oils, other than those classified in 3811.11, 3811.19, 3811.21 and 3811.29.

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

## What it doesn’t cover

Other goods of heading 38.11 are classified under 3811.11 (anti-knock preparations, based on lead compounds), 3811.19 (anti-knock preparations, other), 3811.21 (additives for lubricating oils, containing petroleum oils or oils obtained from bituminous minerals) and 3811.29 (additives for lubricating oils, other).

- [3811.11](https://border.bot/hs-codes/381111) Anti-knock preparations: Based on lead compounds
- [3811.19](https://border.bot/hs-codes/381119) Anti-knock preparations: Other
- [3811.21](https://border.bot/hs-codes/381121) Additives for lubricating oils: Containing petroleum oils or oils obtained from bituminous minerals
- [3811.29](https://border.bot/hs-codes/381129) Additives for lubricating oils: Other

## How it is structured

3811.90 is a six-digit subheading. Its first two digits, 38, are the chapter; the first four, 3811, are heading 38.11; the last two, 90, identify the subheading within the heading.

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

- Chapter 38: Miscellaneous chemical products
- Heading 38.11: Anti-knock preparations, oxidation inhibitors, gum inhibitors, viscosity improvers, anti-corrosive preparations and other prepared additives, for mineral oils (including gasoline) or for other liquids used for the same purposes as mineral oils
- Subheading 3811.90: Other

## In other countries

National tariff lines under 3811.90 are live on border.bot for the United States (1 line, also used by 1 other country).

- [United States](https://border.bot/countries/united-states/hs-codes/381190): 1 line, used by 1 other country

- Previous subheading: [3811.29](https://border.bot/hs-codes/381129) Additives for lubricating oils: Other
- Next subheading: [3812.10](https://border.bot/hs-codes/381210) Prepared rubber accelerators

## Frequently asked questions

### What does HS code 3811.90 cover?

HS code 3811.90 covers anti-knock preparations, oxidation inhibitors, gum inhibitors, viscosity improvers, anti-corrosive preparations and other prepared additives, for mineral oils (including gasoline) or for other liquids used for the same purposes as mineral oils, other than those classified in 3811.11, 3811.19, 3811.21 and 3811.29.

### Which heading and chapter is HS code 3811.90 in?

HS code 3811.90 is in heading 38.11 (anti-knock preparations, oxidation inhibitors, gum inhibitors, viscosity improvers, anti-corrosive preparations and other prepared additives, for mineral oils (including gasoline) or for other liquids used for the same purposes as mineral oils) in chapter 38 (miscellaneous chemical products).

### Where are goods of heading 38.11 classified when 3811.90 doesn’t fit?

Other goods of heading 38.11 are classified under 3811.11 (anti-knock preparations, based on lead compounds), 3811.19 (anti-knock preparations, other), 3811.21 (additives for lubricating oils, containing petroleum oils or oils obtained from bituminous minerals) and 3811.29 (additives for lubricating oils, other).

### Which countries’ tariffs list national lines under HS code 3811.90?

National tariff lines under 3811.90 are live on border.bot for the United States (1 line, 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/381190.json