N,N′-Bis(2-hydroxyethyl)-2-nitro-p-phenylenediamine

N,N′-Bis(2-hydroxyethyl)-2-nitro-p-phenylenediamine (CAS 84041-77-0, EC 281-856-4) is a synthetic nitro-aminophenol dye commercially available under trade names including HC Violet BS, Velsol Violet BS, Jarocol Violet 1.4D, and Violet 1.4D. It carries no assigned E-code and is classified under the broader category of direct hair and textile colorants.

In cosmetic hair colouring, the compound deposits colour on keratin fibres through direct dye affinity without requiring oxidative development, producing violet to blue-violet tones. It is also applied in textile and leather dyeing, where its hydroxyethyl groups improve substantivity to protein and cellulosic substrates, enabling surface-level colour fixation under mildly acidic conditions.

The material is supplied as a powder grade and is subject to REACH registration requirements within the EU. Formulators should verify compliance with Annex III of the EU Cosmetics Regulation, which sets specific concentration limits for this colorant in rinse-off and leave-on applications.