Fragrance avoidance
No fragrance-linked caution surfaced in the current profile.
This ingredient does not currently read as a fragrance-linked driver in the published evidence and hazard profile.
CAS 1361000-03-4 · 70/100 · High conf.
Concern score
Also known as 1H-Pyrazole-4,5- diamine, 1-hexyl-, sulfate (2:1) · 1H-Pyrazole-4,5-diamine, 1-hexyl-, sulfate (2:1) · 1-HEXYL 4,5-DIAMINO pyrazole hemisulfate · bis(1-hexylpyrazole-4,5-diamine);sulfuric acid · 1-Hexyl-1H-pyrazole-4,5-diamine hemisulfate · 1-hexyl-1H-pyrazole-4,5-diamine sulfate (2:1)
1H-Pyrazole-4,5-diamine, 1-hexyl-, sulfate (2:1) · 1H-aPyrazole-a4,a5-adiamine, 1-ahexyl-a, sulfate (2:1) · 2-hexylpyrazole-3,4-diamine;sulfuric acid · 4,5-Diamino-1-n-hexyl-1H-pyrazole hemisulfate · Q27272689 · UNII-9L2QOQ6WFH
Used in cosmetics as a hair dye.
1H-Pyrazole-4,5- diamine, 1-hexyl-, sulfate (2:1) is restricted in cosmetic products under Annex III of the EU Cosmetics Regulation (EC) 1223/2009.
RestrictedEU EC — restricted
The score describes this ingredient's chemical identity — its hazard profile from published classifications and regulatory status — not the safety of any product it appears in.
Restrictions first, then routine listings from published regulatory sources.
EUEC
Annex III of EU Cosmetics Regulation (EC) 1223/2009: substances which cosmetic products must not contain except subject to the restrictions laid down. Product types: Hair dye substance in oxidative hair dye products Other conditions: As from 3 September 2017, after mixing under oxidative conditions the maximum concentration applied to hair must not exceed 1,0 % Conditions of use and warnings: As from 3 March 2018, to be printed on the label: The mixing ratio. ‘Hair colourants can cause severe allergic reactions. Read and follow instructions. This product is not intended for use on persons under the age of 16. Temporary “black henna” tattoos may increase your risk of allergy. Do not colour your hair if: — you have a rash on your face or sensitive, irritated and damaged scalp,…
No expert opinion on file for 1-HEXYL 4,5-DIAMINO pyrazole sulfate. These are the independent scientific bodies that assess ingredients like this one; we show an opinion only when a record we hold cites it.
SCCS
EU Scientific Committee on Consumer Safety
No SCCS opinion on file.
CIR
Cosmetic Ingredient Review (US expert panel)
No CIR safety assessment on file.
No graded research studies for 1-HEXYL 4,5-DIAMINO pyrazole sulfate yet. This record is compiled from the published data sources below — registries and regulatory listings, not study findings.
CosIng
regulatory · updated 2026-09-23
EU CosIng Cosmetics Regulation Annexes
regulatory · updated 2020-07-27
EPA Chemical and Products Database
exposure · updated 2020-02-13
EPA DSSTox Identifiers
chemistry · updated 2025-12-29
FDA GSRS UNII
registry · updated 2026-02-26
openFDA Substance
registry · updated 2026-05-24
PubChem Live Enrichment
chemistry · updated 2026-05-17
Context-specific fit derived from published classifications and the current ingredient evidence profile.
Fragrance avoidance
No fragrance-linked caution surfaced in the current profile.
This ingredient does not currently read as a fragrance-linked driver in the published evidence and hazard profile.