Product classification
HS code for N-phenethyl-4-piperidone: 2933.37
Heterocyclic compounds, containing an unfused pyridine ring (whether or not hydrogenated) in the structure, N-phenethyl-4-piperdone (NPP).
Classification of N-phenethyl-4-piperidone under HS 2933.37
N-phenethyl-4-piperidone (NPP) is classified under HS code 2933.37. This classification is determined by its molecular structure as a heterocyclic compound containing an unfused pyridine ring. Chapter 29 covers organic chemicals, and heading 2933 is reserved for heterocyclic compounds with nitrogen hetero-atom(s) only. Subheading 2933.37 was specifically introduced to the Harmonized System to provide better monitoring of this substance, as it is a primary precursor in the illicit manufacture of fentanyl and its analogues. The classification follows GRI 1, as the chemical name and structure are explicitly described in the subheading text. Because it contains a piperidone structure (a hydrogenated pyridine ring), it falls under the group of compounds with an unfused pyridine ring.
- Covers
- N-phenethyl-4-piperidone (NPP)
- 1-phenethylpiperidin-4-one
- Chemical intermediates for fentanyl synthesis
- NPP hydrochloride salts
- Also under 2933.37
- Cayman Chemical NPP (forensic standard)
- Cerilliant NPP (analytical reference material)
Codes often confused with 2933.37
Common mistake. NPP is sometimes misclassified under 2933.33, which is the code for fentanyl and its derivatives like alfentanil or sufentanil. While NPP is used to make these substances, it is a precursor and not the drug itself. It may also be confused with 2933.39, which is the residual category for other pyridine derivatives. However, since the 2017 HS amendments, 2933.37 is the mandatory specific code for NPP to facilitate international trade monitoring and regulatory compliance.
Top exporters and importers of HS 293337 (the code used for N-phenethyl-4-piperidone), 2025
In 2025, the largest exporter of HS 293337 (the code used for N-phenethyl-4-piperidone) in UN Comtrade data was the United Kingdom, with 75% of world exports; the largest importer in UN Comtrade data was Indonesia, with 70% of world imports. Countries that did not report 2025 data are estimated from partner records, which can understate them.
Figures cover everything classified under HS 293337, not only N-phenethyl-4-piperidone.
Top exporters 2025 · share of world exports
- 1 United Kingdom $1.1M 75% of world exports
- 2 United States $193K 14% of world exports
- 3 France $156K 11% of world exports
World total: $1.4M Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 Indonesia $396K 70% of world imports
- 2 South Africa $85K 15% of world imports
- 3 Egypt $39K 6.9% of world imports
World total: $566K Reported figures on UN Comtrade ↗
How these figures are built
109 countries reported 2025 trade to UN Comtrade in HS 2022, and their own totals are used. Countries that did not report are estimated from what other countries recorded trading with them. Those estimates miss trade with other non-reporting countries, so they can be low, and a non-reporting country can rank higher than shown or be missing from the list. World totals add both and leave out trade between two non-reporting countries. Figures are in current US dollars; reported imports are mostly valued CIF and exports FOB, and exports include re-exports. The UN Comtrade links show the underlying records; they can also list a few reporters left out here (regional groups and older HS editions).
Source: UN Comtrade (United Nations Statistics Division), 2025 annual data.
Brazil NCM code for N-phenethyl-4-piperidone
Brazil classifies N-phenethyl-4-piperidone under NCM 2933.37.00: HS 2933.37 with 00 added.
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.
Questions about N-phenethyl-4-piperidone
What is the HS code for N-phenethyl-4-piperidone?
The HS code for N-phenethyl-4-piperidone is 293337 (Heterocyclic compounds; containing an unfused pyridine ring (whether or not hydrogenated) in the structure, N-phenethyl-4-piperdone (NPP)). The specific HS code for N-phenethyl-4-piperidone (NPP) is 2933.37.
How do I classify N-phenethyl-4-piperidone for customs?
N-phenethyl-4-piperidone is classified under HS code 293337 — Heterocyclic compounds; containing an unfused pyridine ring (whether or not hydrogenated) in the structure, N-phenethyl-4-piperdone (NPP). This is a 6-digit subheading level code.
Why does NPP have its own specific HS code?
It was assigned a specific code to help international authorities monitor the trade of precursor chemicals used in the production of controlled substances.
Which countries are the top exporters of N-phenethyl-4-piperidone (HS 293337)?
In 2025, the top exporters of HS 293337 (the code used for N-phenethyl-4-piperidone) in UN Comtrade data were the United Kingdom ($1.1M, 75% of world exports), the United States ($193K) and France ($156K). World exports came to about $1.4M, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.
Which countries are the top importers of N-phenethyl-4-piperidone (HS 293337)?
In 2025, the top importers of HS 293337 (the code used for N-phenethyl-4-piperidone) in UN Comtrade data were Indonesia ($396K, 70% of world imports), South Africa ($85K) and Egypt ($39K). World imports came to about $566K, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.
Is the HS code for N-phenethyl-4-piperidone the same in all countries?
The base HS code 293337 for N-phenethyl-4-piperidone is internationally standardized for the first 6 digits across 200+ countries. Individual countries may add additional digits for national tariff lines and specific classifications.
What is the NCM code for N-phenethyl-4-piperidone in Brazil?
In Brazil, N-phenethyl-4-piperidone (HS 293337) is classified under NCM 2933.37.00.