HS code · 6-digit subheading
HS Code 2933.37 – Heterocyclic compounds; containing an unfused pyridine ring (whether or not hydrogenated) in the structure, N-phenethyl-4-piperdone (NPP)
HS code 2933.37 is the 6-digit subheading for heterocyclic compounds, containing an unfused pyridine ring (whether or not hydrogenated) in the structure, N-phenethyl-4-piperdone (NPP). It is used for N-phenethyl-4-piperidone, NPP precursor, 1-phenethylpiperidin-4-one and fentanyl precursor NPP.
What HS 2933.37 covers
This HS code covers N-phenethyl-4-piperidone (NPP), another highly controlled precursor chemical essential for the illicit synthesis of fentanyl. International trade of NPP is under severe restrictions and intense scrutiny worldwide, mirroring the controls placed on ANPP. Its primary significance in trade is its role as a key intermediate in the clandestine production of synthetic opioids. Legitimate trade is extremely rare, confined to authorized government laboratories for forensic analysis, research into drug synthesis pathways, or counter-narcotics intelligence, always requiring specific permits and strict regulatory compliance. Importers and exporters are almost exclusively government-sanctioned entities or highly specialized chemical suppliers operating under stringent controls. Key things to know include its designation as a Schedule I or II precursor under international drug control conventions, making its unauthorized trade or possession a serious criminal offense.
- Covers
- N-phenethyl-4-piperidone
- NPP precursor
- 1-phenethylpiperidin-4-one
- Fentanyl precursor NPP
- Examples
- Cayman Chemical NPP (forensic standard)
- Cerilliant NPP (analytical reference material)
Codes often confused with 2933.37
Common mistake. NPP can be mistaken for other piperidone derivatives or other fentanyl precursors, particularly ANPP (HS 2933.36), requiring precise chemical structure verification for correct classification and regulatory compliance.
Top exporters and importers of HS code 293337, 2025
In 2025, the largest exporter of HS code 293337 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.
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 2933.37
Brazil does not split HS 2933.37: its NCM code is 2933.37.00.
All Brazil NCM codes in heading 29.33 →
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text is official; the English is our translation.
Questions about HS 2933.37
What is HS code 293337?
HS code 293337 is a 6-digit subheading in the Harmonized System that covers: Heterocyclic compounds; containing an unfused pyridine ring (whether or not hydrogenated) in the structure, N-phenethyl-4-piperdone (NPP). This HS code covers N-phenethyl-4-piperidone (NPP), another highly controlled precursor chemical essential for the illicit synthesis of fentanyl. International trade of NPP is under severe restrictions and intense scrutiny worldwide, mirroring the controls placed on ANPP. Its primary significance in trade is its role as a key intermediate in the clandestine production of synthetic opioids. Legitimate trade is extremely rare, confined to authorized government laboratories for forensic analysis, research into drug synthesis pathways, or counter-narcotics intelligence, always requiring specific permits and strict regulatory compliance. Importers and exporters are almost exclusively government-sanctioned entities or highly specialized chemical suppliers operating under stringent controls. Key things to know include its designation as a Schedule I or II precursor under international drug control conventions, making its unauthorized trade or possession a serious criminal offense.
What products fall under HS code 293337?
N-phenethyl-4-piperidone, NPP precursor, 1-phenethylpiperidin-4-one, Fentanyl precursor NPP
What are common misclassifications for HS code 293337?
NPP can be mistaken for other piperidone derivatives or other fentanyl precursors, particularly ANPP (HS 2933.36), requiring precise chemical structure verification for correct classification and regulatory compliance.
Which countries are the top exporters of goods under HS code 293337?
In 2025, the top exporters of HS code 293337 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 goods under HS code 293337?
In 2025, the top importers of HS code 293337 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.
How is HS code 293337 structured?
HS code 293337 is a 6-digit subheading under the Harmonized System. The first 2 digits (29) identify the chapter, digits 3-4 (33) identify the heading, and digits 5-6 (37) specify the subheading. This code is standardized globally by the World Customs Organization.
What is the Brazil NCM code for HS code 293337?
In Brazil, HS code 293337 is NCM 2933.37.00. The last two digits are 00 because Brazil does not split this HS code further.