Is CYTOSINE safe to use in EU cosmetics?

CYTOSINE is listed in the EU CosIng ingredient inventory with no direct annex restriction records linked at this time. Always verify against the current official CosIng database before formulating.

What other records share CAS 71-30-7?

CAS 71-30-7 may appear across multiple EU annex records. The CAS lookup page shows all Annex II–VI entries sharing this identifier, useful for identifying cross-annex regulatory status of the same chemical substance.

How do I check if my formula contains CYTOSINE?

Use the INCI Checker to screen a full ingredient list across selected markets, or use the substance market comparison to review this identity across all supported market datasets.

InventoryRef 5557715/10/2010

CYTOSINE

4-Amino-2(1H)-pyrimidinone

CYTOSINE is listed in the EU CosIng inventory, but no direct annex records are linked on this page yet.

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Regulatory evidence by market

No rule for this ingredient has been imported for any of the 13 markets tracked here.

That describes this inventory, not the law. No imported rule is not evidence that an ingredient is permitted: a rule may exist under another name or identifier, or in a dataset not yet imported here.

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Chemical identity and properties

PubChem 2D chemical structure for CAS 71-30-7

CAS 71-30-7PubChem CID 597

Cytosine

Cytosine is an aminopyrimidine that is pyrimidin-2-one having the amino group located at position 4. It has a role as a mouse metabolite, a Saccharomyces cerevisiae metabolite, an Escherichia coli metabolite and a human metabolite. It is a pyrimidine nucleobase, a pyrimidone and an aminopyrimidine. — ChEBI

IUPAC name: 6-amino-1H-pyrimidin-2-one

Molecular formula: C4H5N3O
Molecular weight: 111.10 g/mol
Exact mass: 111.043261792 Da
XLogP3: -1.7
Topological polar surface area: 67.5 Å²
Hydrogen-bond donors: 2
Hydrogen-bond acceptors: 2
Covalent units: 1
Defined stereocentres: 0

Also known as

4-aminopyrimidin-2(1H)-one4-Amino-2-hydroxypyrimidineCytosinimine2(1H)-Pyrimidinone, 4-amino-4-Amino-2(1H)-pyrimidinoneNSC-277878J337D1HZYCHEBI:16040

16 more reported names

4-amino-3h-pyrimidin-2-one6-amino-1,2-dihydropyrimidin-2-oneRefChem:5728200-749-54-Aminouracil6-Aminopyrimidin-2(1h)-One4-aminopyrimidin-2-olCytosin4-amino-2-pyrimidinol2(1H)-pyrimidinone, 6-amino-4-amino-2-oxo-1,2-dihydropyrimidineZytosinCytAI3-522816-amino-3-hydropyrimidin-2-onepyrimidine, 4-amino-2-hydroxy-

Open full PubChem record PubChem annotations 3D structure image

External database identifiers

ChEBI:CHEBI:16040
ChEMBL:CHEMBL15913
EPA DTXSID:DTXSID4044456
PubMed:23101657
PubMed:23098078
PubMed:23075701
PubMed:23073584
PubMed:23067126
PubMed:23044366
PubMed:23032709
PubMed:23028748
PubMed:23019171
PubMed:23018623
PubMed:23015417
PubMed:23000573

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

Inventory details for CYTOSINE

INCI name

CYTOSINE

Description

4-Amino-2(1H)-pyrimidinone

Record provenance

Inventory reference: 55577
Imported identity: CYTOSINE
Source update: 15/10/2010

European Commission CosIng source notes

Annex records for CYTOSINE

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Key data

CAS

71-30-7

200-749-5

Restriction

—

Function

SKIN CONDITIONING: Maintaining the skin in good condition.

Official EU ingredient-name evidence

The ingredient name exactly matches the official 2025 EU glossary of common ingredient names.

#8000 · CYTOSINE

Ingredients with overlapping formulation functions

CYTISUS SCOPARIUS FLOWER CERASKIN CONDITIONING

CYTISUS SCOPARIUS FLOWER EXTRACTFRAGRANCE, SKIN CONDITIONING

CYTISUS SCOPARIUS FLOWER WAXSKIN CONDITIONING

CYTOCHROME CSKIN CONDITIONING

D-HEPTAPEPTIDE-1SKIN CONDITIONING

D-NONAPEPTIDE-1SKIN CONDITIONING

D-NONAPEPTIDE-1 DIPEPTIDE-15 D-HEPTAPEPTIDE-1 D-NONAPEPTIDE-2 GLYCINAMIDESKIN CONDITIONING

D-NONAPEPTIDE-2SKIN CONDITIONING

Additional official and scientific sources

11 external databases to check this identity in

Each link searches that source for this identity. What each source is, and its legal weight

ECHA CHEM / Information on chemicals PubChem PUG REST EU Safety Gate cosmetic product alerts ECHA CHEM US EPA CompTox Cosmetic Ingredient Review safety assessments FDA Global Substance Registration System ILO/WHO International Chemical Safety Cards Japan NITE-CHRIP NIOSH Pocket Guide to Chemical Hazards OECD eChemPortal

How CYTOSINE appears in the CosIng inventory

The CosIng inventory lists CYTOSINE as a cosmetic ingredient and this page links it to 0 annex records. The inventory entry captures names and identifiers, while the annex records show where the substance is prohibited, restricted or positively listed in EU cosmetics law.

CYTOSINE is also tagged with 1 cosmetic function in the official data. Function labels describe intended use, but they do not replace regulatory review of linked annex records before formulation or labelling work.

Frequently asked questions

CYTOSINE is listed in the EU CosIng ingredient inventory with no direct annex restriction records linked at this time. Absence of an annex link does not guarantee unrestricted use — always verify against the current official CosIng database before formulating.

According to the EU CosIng inventory, CYTOSINE carries the following function designation(s):

SKIN CONDITIONING

CAS 71-30-7 may appear across multiple EU annex records. Viewing the CAS lookup page shows all Annex II–VI entries sharing this identifier, which is useful for identifying cross-annex regulatory status of the same chemical substance.

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Source note for CYTOSINE

This page reproduces the CosIng inventory entry for CYTOSINE from public European Commission cosmetic ingredient materials and shows linked identifiers even when no direct annex match is currently attached.

Use this inventory page to research CYTOSINE and compare linked records, but verify restrictions and legal status against the current official source text and law before making regulatory decisions.

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