2933.52 Heterocyclic compounds; containing a pyrimidine ring (whether or not hydrogenated) or piperazine ring in the structure, malonylurea (barbituric acid) and its salts
A full HS code. These six digits are what goes on a customs declaration, and they mean the same thing in every country that uses the Harmonized System.
Section VI, Chemical Products — inorganic and organic chemicals, pharmaceuticals, fertilisers, paints and cosmetics.
- 29 Chapter Organic chemicals
- 33 Heading Heterocyclic compounds with nitrogen hetero-atom(s) only
- 52 Subheading Heterocyclic compounds; containing a pyrimidine ring (whether or not hydrogenated) or piperazine ring in the structure, malonylurea (barbituric acid) and its salts
Chapter 29 covers organic chemicals: hydrocarbons, alcohols, acids, esters and other carbon-based compounds that feed into pharmaceuticals, plastics, solvents and countless other manufactured goods. With over 400 six-digit codes it's the single largest chapter in the entire Harmonized System, since organic chemistry produces so many distinct, precisely defined compounds. Classification tip: Because chapter 29 is organized by precise chemical structure (not by end use), classification usually requires the compound's exact chemical name or CAS number: a generic product description is rarely enough to pick the right six-digit code.
All of chapter 29Other codes under 29.33
The wording above is the Harmonized System nomenclature as published by the World Customs Organization, HS 2022 edition. It is a classification reference, not a tariff: it carries no duty rates, and it stops at six digits — the importing country adds its own beyond that.
Classification is decided by the General Rules of Interpretation and the section and chapter notes, and it is the importing country’s customs authority that makes it binding.
Shipping goods under 2933.52? A customs hold shows up as a milestone that stops moving — follow the container or the air waybill from departure to delivery.
Track a shipment2933.52 FAQ
2933.52 covers heterocyclic compounds; containing a pyrimidine ring (whether or not hydrogenated) or piperazine ring in the structure, malonylurea (barbituric acid) and its salts. It sits under heading 29.33 (heterocyclic compounds with nitrogen hetero-atom(s) only) in chapter 29, Section VI of the Harmonized System.
It is the international part of it. Six digits are the same in every country that applies the Harmonized System; the importing country then extends them to eight or ten for its own tariff and statistics. Declare 2933.52 plus whatever national digits the destination’s tariff schedule adds to it.
The General Rules of Interpretation, read together with the notes to Section VI and to chapter 29. A description that reads right is not enough on its own — the notes routinely pull goods out of the chapter they obviously belong to and put them somewhere else. Where duty or licensing turns on the answer, ask the importing country’s customs authority for a binding ruling.
A wrong or missing code is one of the common reasons customs holds a container, and a hold shows up as a milestone that stops moving. Watch for it in the container tracking app, on the air waybill in the air cargo tracker, or through the tracking API.