Common Name(s): Basic red 51,cationic red dye

CAS Number: 77061-58-6

DESCRIPTION

What It Does: Provides intense cationic direct red hair colouring with improved adherence to damaged hair.

Why It's Used: Premium fashion red direct dye with enhanced substantivity for better colour deposit on damaged, bleached hair.

How It Works: Cationic (positively charged) structure electrostatically adsorbs to negatively charged bleached/damaged hair with higher affinity than non-ionic direct dyes. intense red chromophore provides vivid fashion red. difficult to fully remove once deposited.

Typically Found In: Fashion hair colour,intense red hair products

TECHNICAL DETAILS

Primary Category: Hair colourant – basic direct dye

Secondary Functions: Skin conditioning

Application Areas:

Typical Concentration Range: 0.1%–2%

SOURCING & ETHICS

Vegan Status: Conditional - supplier confirmation required

Halal Status: Unverified - supplier confirmation required

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier. [audit 2026-07-29 rev2: the record's own source_notes does not assert a non-animal origin, or instructs the reader to verify with the supplier; "yes" asserts knowledge the record does not hold. determination requires shariah-panel sign-off.]

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Eu annex iii restricted for hair use.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Basic dye substantivity to hair follows the same electrochemical principle as cationic conditioners: positively charged dye cations adsorb to the negatively charged hair cuticle via electrostatic attraction. bleached/highlighted hair has more exposed anionic groups (more negative charge), causing preferential basic dye deposition on treated hair vs virgin hair – the same targeting principle as amodimethicone conditioning.

Last Verified: 2026-03-12

Primary Sources: Cosing database,eu annex iii hair dye list