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Annex II Entry 1590 CMR30/07/2020

Lenacil (ISO); 3-cyclohexyl-6,7-dihydro-1H-cyclopenta[d]pyrimidine-2,4(3H,5H)-dione

Lenacil (ISO); 3-cyclohexyl-6,7-dihydro-1H-cyclopenta[d]pyrimidine-2,4(3H,5H)-dione is listed in Annex II as a prohibited substance for cosmetic products placed on the EU market.

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Prohibited substance— Annex II, EU Regulation 1223/2009
Entry: 1590
CMR

Chemical identity and properties

PubChem 2D chemical structure for CAS 2164-08-1
CAS 2164-08-1PubChem CID 16559

Lenacil

Lenacil is a cyclopentapyrimidine that is 6,7-dihydro-1H-cyclopenta[d]pyrimidine-2,4(3H,5H)-dione substituted by a cyclohexyl group at position 3. It has a role as a herbicide, an agrochemical, a xenobiotic and an environmental contaminant. — ChEBI

IUPAC name
3-cyclohexyl-1,5,6,7-tetrahydrocyclopenta[d]pyrimidine-2,4-dione
Molecular formula
C13H18N2O2
Molecular weight
234.29 g/mol
Exact mass
234.136827821 Da
XLogP3
1.7
Topological polar surface area
49.4 Ų
Hydrogen-bond donors
1
Hydrogen-bond acceptors
2
Covalent units
1
Defined stereocentres
0

Also known as

Venzar3-Cyclohexyl-5,6-trimethyleneuracilDu Pont 634X58DK6S8KXCHEBI:64073-Cyclohexyl-6,7-dihydro-1H-cyclopentapyrimidine-2,4(3H,5H)-dione3-Cyclohexyl-1,5,6,7-tetrahydrocyclopentapyrimidine-2,4(3H)-dionehexylure
16 more reported names
3-cyclohexyl-1,5,6,7-tetrahydrocyclopenta(d)pyrimidine-2,4-dioneRefChem:152739218-499-0ElbatanHexilureBuracylAdol (pesticide)Herbicide 634Uracil 634LenacileExperimental herbicide 6343-cyclohexyl-6,7-dihydro-1H-cyclopenta[d]pyrimidine-2,4(3H,5H)-dione3-Cyclohexyl-5,6-trimethylenuracil1H-Cyclopentapyrimidine-2,4(3H,5H)-dione, 6,7-dihydro-3-cyclohexyl-3-Cyclohexyl-6,7-dihydro-1H-cyclopentapyrimidine-2,4-(3H,5H)-dione1H-Cyclopentapyrimidine-2,4(3H,5H)-dione, 3-cyclohexyl-6,7-dihydro-
Open full PubChem recordPubChem annotations3D structure image
External database identifiers

Retrieved from NIH PubChem on 2026-09-02 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.

Record details

Chemical name

Lenacil (ISO); 3-cyclohexyl-6,7-dihydro-1H-cyclopenta[d]pyrimidine-2,4(3H,5H)-dione

Chemical / IUPAC name

Lenacil (ISO); 3-cyclohexyl-6,7-dihydro-1H-cyclopenta[d]pyrimidine-2,4(3H,5H)-dione

Regulatory information

Regulation

(EU) 2019/831

See every entry this act set

CMR

CategoryCarcinogenicMutagenicReprotoxic
Cat. 2✓——

Key data

CAS
2164-08-1
EC
218-499-0
Annex
II
Entry number
1590

Direct matches are limited for this record, so nearby entries from Annex II are shown as well.

Annex II 1589
Nearby record in the same annex

Imidazole

CAS: 288-32-4
EC: 206-019-2

What Annex II means for Lenacil (ISO); 3-cyclohexyl-6,7-dihydro-1H-cyclopenta[d]pyrimidine-2,4(3H,5H)-dione

Lenacil (ISO); 3-cyclohexyl-6,7-dihydro-1H-cyclopenta[d]pyrimidine-2,4(3H,5H)-dione is listed as a prohibited substance under Annex II of EU Cosmetics Regulation 1223/2009 and must not be intentionally added. Article 17 separately addresses unintended small quantities that are technically unavoidable under good manufacturing practice and compatible with the Article 3 safety requirement.

Formulators must screen their ingredients and raw materials to ensure none contain this substance. Suppliers should provide documentation confirming absence when requested.

The page also surfaces 12 related annex records with overlapping identifiers, annex logic or naming patterns.

Compliance checklist

  • Verify this substance is absent from all raw materials and finished formulations.
  • Request absence confirmation or CoA from raw material suppliers.
  • Document the screening result in the Product Information File (PIF).
  • This substance has CMR classification. Review the CMR table above and verify current Annex II/III status before use.

Frequently asked questions

Yes. Lenacil (ISO); 3-cyclohexyl-6,7-dihydro-1H-cyclopenta[d]pyrimidine-2,4(3H,5H)-dione is listed in Annex II of EU Cosmetics Regulation 1223/2009 and is prohibited as an intentionally added cosmetic ingredient. Article 17 provides a narrow exception for unintended small quantities that are technically unavoidable under good manufacturing practice, provided the product remains safe under Article 3.

CAS 2164-08-1 is the unique numerical identifier assigned to Lenacil (ISO); 3-cyclohexyl-6,7-dihydro-1H-cyclopenta[d]pyrimidine-2,4(3H,5H)-dione by the Chemical Abstracts Service. In cosmetic compliance work, the CAS number is used to cross-reference the substance across regulatory databases, raw material specifications and safety assessment reports. Multiple EU annex entries may share the same CAS number if the same substance appears under different conditions or in different annexes.

Lenacil (ISO); 3-cyclohexyl-6,7-dihydro-1H-cyclopenta[d]pyrimidine-2,4(3H,5H)-dione has a CMR (carcinogenic, mutagenic or reprotoxic) classification under EU CLP Regulation. Under Article 15 of EU Cosmetics Regulation 1223/2009, CMR substances of category 1A or 1B are prohibited in cosmetics unless specifically permitted. Category 2 CMR substances may be used only if assessed safe by the SCCS. Always verify current annex status and any applicable derogations before use.

Use the INCI Checker tool on this site to paste your full ingredient list (INCI) and scan it against all Annex II–VI entries. The tool highlights any ingredients that match restricted, prohibited or allergen-flagged records. This is useful for rapid compliance screening of finished product formulas or raw material declarations.
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Source note for Annex II record Lenacil (ISO); 3-cyclohexyl-6,7-dihydro-1H-cyclopenta[d]pyrimidine-2,4(3H,5H)-dione

This page summarizes one Annex II record for Lenacil (ISO); 3-cyclohexyl-6,7-dihydro-1H-cyclopenta[d]pyrimidine-2,4(3H,5H)-dione from public European Commission cosmetic materials and adds linked inventory or identifier matches when available.

Use this record page to review Annex II conditions for Lenacil (ISO); 3-cyclohexyl-6,7-dihydro-1H-cyclopenta[d]pyrimidine-2,4(3H,5H)-dione, but confirm any final regulatory decision against the current official annex wording and source files.

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