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Annex II Entry 749 CMR15/10/2010

Diethyl sulphate

Diethyl sulphate 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: 749
CMR

Chemical identity and properties

PubChem 2D chemical structure for CAS 64-67-5
CAS 64-67-5PubChem CID 6163

Diethyl Sulfate

Diethyl sulfate is the diethyl ester of sulfuric acid. It has a role as an alkylating agent, a mutagen, a carcinogenic agent and an apoptosis inducer. — ChEBI

IUPAC name
diethyl sulfate
Molecular formula
C4H10O4S
Molecular weight
154.19 g/mol
Exact mass
154.02997997 Da
XLogP3
1.1
Topological polar surface area
61.0 Ų
Hydrogen-bond donors
0
Hydrogen-bond acceptors
4
Covalent units
1
Defined stereocentres
0

Also known as

Diethyl sulphateSulfuric acid, diethyl esterDIETHYLSULFATEDiaethylsulfatSulfuric acid diethyl esterDiethyl tetraoxosulfateDiethylester kyseliny siroveK0FO4VFA7I
16 more reported names
NSC-56380CHEBI:34699RefChem:133445Sufuric Acid Diethyl Ester200-589-6Montelukast Impurity 15NSC 56380Ethyl sulfate (Et2SO4)ethyl ethoxysulfonateDiaethylsulfat [German]DES (VAN)CAS-64-67-5Diethyl MonosulfateCCRIS 242HSDB 1636Diethylester kyseliny sirove [Czech]
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External database identifiers

Retrieved from NIH PubChem on 2026-08-31 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.

Record details

Chemical name

Diethyl sulphate

Regulatory information

Regulation

(EC) 2009/1223

See every entry this act set

SCCS opinions

CMR

CategoryCarcinogenicMutagenicReprotoxic
Cat. 1B✓✓—

Key data

CAS
64-67-5
EC
200-589-6
Annex
II
Entry number
749

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

Annex II 753
Nearby record in the same annex

Sulfallate

CAS: 95-06-7
EC: 202-388-9
Annex II 744
Nearby record in the same annex

Formamide

CAS: 75-12-7
EC: 200-842-0
Annex II 742
Nearby record in the same annex

Thioacetamide

CAS: 62-55-5
EC: 200-541-4

What Annex II means for Diethyl sulphate

Diethyl sulphate 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. Diethyl sulphate 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 64-67-5 is the unique numerical identifier assigned to Diethyl sulphate 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.

Diethyl sulphate 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 Diethyl sulphate

This page summarizes one Annex II record for Diethyl sulphate 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 Diethyl sulphate, but confirm any final regulatory decision against the current official annex wording and source files.

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