What does the restriction note for MERCURIC OXIDE mean?

The restriction field for MERCURIC OXIDE reads: II/221. This is the restriction note from the CosIng inventory. For authoritative conditions and limits, always refer to the linked annex entries.

What other records share CAS 21908-53-2?

CAS 21908-53-2 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 MERCURIC OXIDE?

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 8496515/10/2010

MERCURIC OXIDE

MERCURIC OXIDE is linked to 1 EU annex record on this page. Inventory note: II/221.

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Regulatory evidence by market

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Market	Evidence status	Records	Source language
European Union	Evidence linked Prohibited entry found Open this evidence	1	English and EU languages
Great Britain	Source mapped Official source mapped; ingredient rule not imported	0	English
Canada	Evidence linked Prohibited Open this evidence	1	English and French
New Zealand	Source mapped Official source mapped; ingredient rule not imported	0	English
ASEAN	Source mapped Official source mapped; ingredient rule not imported	0	English and national languages
China	Source mapped Official source mapped; ingredient rule not imported	0	Chinese with selected English material
Japan	Source mapped Official source mapped; ingredient rule not imported	0	Japanese; official English translation available
South Korea	Source mapped Official source mapped; ingredient rule not imported	0	Korean with some English names
United States	Source mapped Official source mapped; ingredient rule not imported	0	English
Australia	Source mapped Official source mapped; ingredient rule not imported	0	English
Brazil	Source mapped Official source mapped; ingredient rule not imported	0	Portuguese with INCI crosswalks
India	Source mapped Official source mapped; ingredient rule not imported	0	English and Hindi
Saudi Arabia	Source mapped Official source mapped; ingredient rule not imported	0	Arabic and English

Chemical identity and properties

PubChem 2D chemical structure for CAS 21908-53-2

CAS 21908-53-2PubChem CID 30856

Mercuric oxide

Mercuric oxide, [solid] appears as red or orange-red odorless, dense crystalline powder or scales, yellow when finely powdered. Used as a chemical intermediate for mercury salts, organic mercury compounds, and chlorine monoxide; antiseptic in pharmaceuticals; component of dry cell batteries; pigment and glass modifier; fungicide; preservative in cosmetics; analytical reagent; formerly used in antifouling paints. (EPA, 1998) — CAMEO Chemicals

IUPAC name: oxomercury

Molecular formula: HgO
Molecular weight: 216.59 g/mol
Exact mass: 217.965558 Da
Topological polar surface area: 17.1 Å²
Hydrogen-bond donors: 0
Hydrogen-bond acceptors: 1
Covalent units: 1
Defined stereocentres: 0

Also known as

Mercury(II) oxideMercuric oxide, redSantarRed PrecipitateRed mercuric oxideMercury oxide (HgO)Mercuric oxide, yellowSantar M

16 more reported names

Yellow precipitateMercuric oxide redNatural montroyditeMercury(2+) oxideRed oxide of mercuryGelbes quecksilberoxydHydrargyrum oxid flavYellow mercuric oxideMercuric oxide (red)Oxide mercurique jauneMercuric oxide (HgO)Caswell No. 544AYellow oxide of mercuryOxido amarillo de mercurioOxyde de mercureEPA Pesticide Chemical Code 052102

Open full PubChem record PubChem annotations 3D structure image

External database identifiers

EPA DTXSID:DTXSID4042125
PubMed:16216453
PubMed:15649619
PubMed:15071173
PubMed:14692620
PubMed:12606766
PubMed:11896293
PubMed:11277574

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

Inventory details for MERCURIC OXIDE

INCI name

MERCURIC OXIDE

Record provenance

Inventory reference: 84965
Imported identity: MERCURIC OXIDE
Source update: 15/10/2010

European Commission CosIng source notes

Annex records for MERCURIC OXIDE

Annex II Restriction reference

Entry 221

Mercury and its compounds, except those special cases included in Annex V

CAS: 7439-97-6

EC: 231-106-7

Key data

CAS

21908-53-2

244-654-7

Restriction

II/221

Function

ANTIMICROBIAL: Preventing and/or slowing down microbial growth.

Official EU ingredient-name evidence

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

#16266 · MERCURIC OXIDE

Ingredients with overlapping formulation functions

MELALEUCA ALTERNIFOLIA LEAF WATERANTI-SEBUM, ANTIMICROBIAL, ASTRINGENT, TONIC

MELIA AZADIRACHTA BARK EXTRACTANTIMICROBIAL, SKIN PROTECTING

MELILOTUS ALBUS FLOWER/LEAF/STEM EXTRACTANTIMICROBIAL, ANTIOXIDANT

MENTHA SUAVEOLENS FLOWER OILANTIMICROBIAL

METHENAMINEANTIMICROBIAL, PRESERVATIVE

METHYL AMINOLEVULINATE HCLANTIMICROBIAL, ANTIOXIDANT, SKIN PROTECTING

METHYLBENZETHONIUM CHLORIDEANTIMICROBIAL, ANTISTATIC, DEODORANT, SURFACTANT - CLEANSING

METHYLSELENO CARBOXYETHYLGLUTAMINEANTI-SEBORRHEIC, ANTIMICROBIAL, ANTIOXIDANT, HAIR CONDITIONING, SKIN CONDITIONING, SKIN PROTECTING

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 MERCURIC OXIDE appears in the CosIng inventory

The CosIng inventory lists MERCURIC OXIDE as a cosmetic ingredient and this page links it to 1 annex record. The inventory entry captures names and identifiers, while the annex record shows where the substance is prohibited, restricted or positively listed in EU cosmetics law.

MERCURIC OXIDE 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

MERCURIC OXIDE appears in the EU CosIng inventory and has linked annex records. Check the annex records above for applicable restrictions, concentration limits and conditions of use. Annex II listing means prohibited; Annex III means restricted; Annexes IV, V and VI mean permitted under specified conditions.

The restriction field for MERCURIC OXIDE reads: "II/221". This is the restriction note recorded in the CosIng inventory for this ingredient. For authoritative conditions and limits, always refer to the linked annex entries above.

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

ANTIMICROBIAL

CAS 21908-53-2 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 MERCURIC OXIDE

This page combines the CosIng inventory entry for MERCURIC OXIDE with 1 linked Annex II–VI record from the local dataset built from public European Commission cosmetic ingredient materials.

Use this inventory page to research MERCURIC OXIDE 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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Tools & next steps

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