Most lubricant additives fall under Harmonized System heading 3811: 3811.21 when the additive is carried in petroleum oil, and 3811.29 when it isn’t. But not all of them — a defined chemical compound is classified by its own chemistry under Chapter 29, and a polymer in primary form under Chapter 39.
If you are filing customs paperwork and need the lubricant additives HS code, the practical answer depends on what the additive actually is. We prepare the export codes and shipping documents for our additive shipments, so this guide is written from that seat — for importers, procurement teams, and formulators who need the correct tariff line before a shipment moves. Classify it wrong and you risk clearance delays, reclassification, or duty adjustments; classify it right and the invoice, packing list, and SDS all agree. The six-digit code is standardized worldwide; the eight- to ten-digit extension is country-specific.
Who this guide is for: anyone confirming the tariff line for a specific lubricant additive before ordering or importing it.
Which HS code applies to lubricant additives?
Prepared additives for lubricating oils sit in heading 3811 — the World Customs Organization heading for anti-knock preparations, oxidation and gum inhibitors, viscosity improvers, anti-corrosive preparations, and other prepared additives for mineral oils (including gasoline) or similar liquids. Lubricating-oil additives resolve to 3811.21 or 3811.29. The U.S. general (column 1) duty for both is 6.5%, before any preferential-program or trade-remedy duties — such as Section 301 measures on China-origin goods — that your import customs authority applies.
That heading is your starting point, not a guarantee: whether an additive stays in 3811 depends on how it is presented — which is where most classification mistakes begin.
3811.21 or 3811.29 — what actually separates them?
The dividing line is the carrier. 3811.21 covers prepared additives that contain petroleum oil or oils from bituminous minerals; 3811.29 is everything else. In eight-digit tariff schedules these appear as 3811.21.00 (rendered 38112100) and 3811.29.00 (38112900). In practice, most finished detergent, dispersant, and antiwear additives are supplied in a diluent oil, so they land in 3811.21 — our overbased calcium sulfonate detergent and ZDDP antiwear additive are typical examples. Additives with no petroleum-oil carrier — sulfurized esters, organomolybdenum compounds, some demulsifiers — move to 3811.29.
Before you declare, check one thing: is the product an oil-carried preparation or not? That single fact usually decides 21 versus 29.
When a lubricant additive is NOT classified under 3811
Here is what the customs databases and most guides miss. When an additive is a separate chemically defined organic compound, it is classified by its own chemistry under Chapter 29 — not 3811. When it is a polymer in primary form, it falls under Chapter 39.
That is why our BHT antioxidant and mixed-phenol antioxidants sit under 2907.19 (phenols), octylated butylated diphenylamine under 2921.44, and a benzotriazole metal deactivator under 2933.99 (heterocyclic nitrogen compounds). On the polymer side, polyisobutylene is 3902.20 and our PDMS silicone defoamer is 3910.00. The same functional “additive” can land in three different chapters depending on its form — which is exactly why a blanket “it’s 3811” is often wrong. Our full range of lubricant additive components spans all three.
From the labSpeccing a hydraulic, gear or turbine oil? CheMost supplies the chemistry.Browse industrial packagesHS codes for common lubricant additive families (our export practice)
| Additive family | HS code (CheMost export) | Chapter logic |
|---|---|---|
| Overbased / high-based calcium & magnesium sulfonate | 3811.21 | Prepared additive, oil-carried |
| Zinc dialkyldithiophosphate (ZDDP) | 3811.21 | Prepared additive, oil-carried |
| PIB succinimide dispersant | 3811.21 | Prepared additive, oil-carried |
| Sulfurized olefin / isobutylene (EP) | 3811.29 | Prepared additive, no oil carrier |
| Molybdenum dithiocarbamate (MoDTC / MoDTP) | 3811.29 | Prepared additive, other |
| BHT / mixed-phenol antioxidant | 2907.19 | Defined phenol compound (Ch. 29) |
| Octylated butylated diphenylamine | 2921.44 | Diphenylamine derivative (Ch. 29) |
| Benzotriazole metal deactivator | 2933.99 | Heterocyclic-nitrogen compound (Ch. 29) |
| Polyisobutylene (PIB) | 3902.20 | Polymer in primary form (Ch. 39) |
| Polydimethylsiloxane (PDMS) defoamer | 3910.00 | Silicone in primary form (Ch. 39) |
This map shows how one functional category splits across three HS chapters depending on form.
Sourcing any of these families? Request a sample and quote and we will confirm the exact export code, SDS, and COA for your grade.
6-digit vs 8-digit: who is responsible for the final code?
The six-digit subheading is harmonized globally; the eight- to ten-digit tail is national — the U.S. HTS and the Chinese export tariff schedule each extend it their own way. On our side, we declare the correct eight-digit CN export code on the commercial invoice and packing list, and we give buyers the six-digit code for their own import filing. See our export compliance documentation and the export documents we provide for what ships with every order.
What we do not do is decide the final code for your country — that is your import customs authority’s call. A published U.S. CBP ruling, for instance, classified a commercial additive package under 3811.21, but a ruling binds only the jurisdiction that issued it. When you request a sample or a quote, ask the supplier for the six-digit HS code plus the SDS and COA — not just a generic “3811.”
Frequently asked questions
What is the HS code for lubricant additives?
Most are 3811.21 (additives containing petroleum oil) or 3811.29 (additives without it). Additives that are defined chemical compounds or polymers are the exception and are classified under Chapters 29 and 39 respectively.
What is the difference between HS 3811.21 and 3811.29?
The presence of a petroleum-oil carrier. 3811.21 is for prepared additives that contain petroleum or bituminous-mineral oils; 3811.29 covers prepared lubricant additives that do not.
Are all lubricant additives classified under 3811?
No. A chemically defined additive follows its own chemistry — BHT is 2907.19, benzotriazole is 2933.99 — and a polymer such as polyisobutylene is 3902.20. Only prepared additive formulations stay in 3811.
Is the six-digit HS code the same in every country?
Yes for the first six digits, which the World Customs Organization harmonizes worldwide. The eight- to ten-digit extension, and the duty rate, are set nationally — in the United States that national extension is the Harmonized Tariff Schedule (HTS) — and can differ between the export and import countries.
Who determines the final HS code, the supplier or the buyer?
The exporter declares the export code and provides the six-digit HS code; the importer’s customs authority makes the final classification decision for the destination country.
About this guide
Prepared by CheMost’s export documentation team from the U.S. Harmonized Tariff Schedule, WCO nomenclature, and our own product export classifications. Last reviewed July 2026.
Need the exact HS code, SDS, and COA for a specific additive? Request the code and datasheet.
References & Industry Standards
- U.S. International Trade Commission — Harmonized Tariff Schedule, heading 3811.
- World Customs Organization — Harmonized System Nomenclature.
Related Articles
