Is GUANIDINE HCL safe to use in EU cosmetics?

GUANIDINE HCL 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 50-01-1?

CAS 50-01-1 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 GUANIDINE HCL?

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 3417315/10/2010

GUANIDINE HCL

Guanidinium chloride

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

INCI Checker Compare all markets Search similar

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.

Markets and their official sources Search every market for this name

Chemical identity and properties

PubChem 2D chemical structure for CAS 50-01-1

CAS 50-01-1PubChem CID 5742

Guanidine Hydrochloride

Guanidine Hydrochloride is the hydrochloride salt form of guanidine, a strong basic compound with parasympathomimetic activity. Guanidine hydrochloride enhances the release of acetylcholine following a nerve impulse and potentiates acetylcholine actions on muscarinic and nicotinic receptors. It also appears to slow the rates of depolarization and repolarization of muscle cell membranes. (NCI05) — NCI Thesaurus (NCIt)

IUPAC name: guanidine;hydrochloride

Molecular formula: CH6ClN3
Molecular weight: 95.53 g/mol
Exact mass: 95.0250249 Da
Topological polar surface area: 75.9 Å²
Hydrogen-bond donors: 4
Hydrogen-bond acceptors: 1
Covalent units: 2
Defined stereocentres: 0

Also known as

Guanidinium chlorideguanidine HClAminoformamidine hydrochlorideGUANIDINE MONOHYDROCHLORIDECarbamidine hydrochlorideAminomethanamidine hydrochlorideIminourea hydrochloride3YQC9ZY4YB

16 more reported names

NSC-755884Chloride, GuanidiniumGuanidium chlorideCHEBI:32735Chloride, GuanidiumHydrochloride, GuanidineRefChem:58639Monohydrochloride, Guanidine200-002-3Guanidine, monohydrochlorideGuanidine chlorideGuanidine (hydrochloride)GuanidinehydrochlorideCH6ClN3Guanidinium hydrochlorideGuanidine-13C hydrochloride

Open full PubChem record PubChem annotations 3D structure image

External database identifiers

ChEMBL:CHEMBL1200728
EPA DTXSID:DTXSID7058757
PubMed:1117

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 GUANIDINE HCL

INCI name

GUANIDINE HCL

Description

Guanidinium chloride

Record provenance

Inventory reference: 34173
Imported identity: GUANIDINE HCL
Source update: 15/10/2010

European Commission CosIng source notes

Annex records for GUANIDINE HCL

Browse

Browse EU annexes

Explore Annex II–VI to see which substances are prohibited, restricted or permitted under specific conditions.

Search annex entries

Search the annex database for entries matching GUANIDINE HCL or related substances.

Key data

CAS

50-01-1

200-002-3

Restriction

—

Function

BUFFERING: Stabilising the pH of an aqueous medium in a narrow range even if an acid or base is added. Altering and/or maintaining a cosmetic product's pH at the desired level.

Official EU ingredient-name evidence

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

#11493 · GUANIDINE HCl

Ingredients with overlapping formulation functions

GLYCINE HCLBUFFERING

GLYCOLIC ACIDBUFFERING

GLYOXYLIC ACIDANTISTATIC, BUFFERING, HAIR WAVING OR STRAIGHTENING

GUANIDINE CARBONATEBUFFERING, SKIN CONDITIONING

HUMAN DERMAL FIBROBLAST STEM CELL EXOSOMESBUFFERING; HAIR CONDITIONING; EYELASH CONDITIONING; SKIN CONDITIONING - MISCELLANEOUS

HYDROBROMIC ACIDBUFFERING

HYDROCHLORIC ACIDBUFFERING

HYDROXYECTOINBUFFERING, SKIN CONDITIONING, SKIN CONDITIONING - EMOLLIENT

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 GUANIDINE HCL appears in the CosIng inventory

The CosIng inventory lists GUANIDINE HCL 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.

GUANIDINE HCL 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

GUANIDINE HCL 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, GUANIDINE HCL carries the following function designation(s):

BUFFERING

CAS 50-01-1 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.

View CAS records

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

Open INCI Checker

Source note for GUANIDINE HCL

This page reproduces the CosIng inventory entry for GUANIDINE HCL 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 GUANIDINE HCL and compare linked records, but verify restrictions and legal status against the current official source text and law before making regulatory decisions.

View sources View updates

Tools & next steps

Check your formula

Scan a full INCI list to detect GUANIDINE HCL and any linked EU annex restrictions or allergen flags.

INCI Checker

Search similar ingredients

Find other inventory ingredients and annex entries related to GUANIDINE HCL, its identifiers or nearby name variants.