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HC RED NO. 9

Description

HC Red No. 9, also known as 2-[(2-Hydroxyethyl)amino]-5-nitrophenol, is a synthetic hair dye ingredient commonly used in semi-permanent and temporary hair coloring products. This water-soluble compound imparts vibrant red tones to hair, ranging from deep burgundy to bright cherry hues. HC Red No. 9 is particularly effective on pre-lightened or naturally light hair, providing intense color results without the need for oxidative processes.

The molecule's structure allows it to penetrate the hair shaft partially, adhering to the cuticle and cortex layers. This results in a color that gradually fades over multiple washes, typically lasting 4-6 weeks. HC Red No. 9 is often combined with other HC dyes to create custom shades and improve color stability. Its non-oxidative nature makes it gentler on hair compared to permanent dyes, reducing the risk of damage and breakage.

Safety assessments have shown HC Red No. 9 to be generally safe for use in hair dyes when applied according to manufacturer instructions. However, as with all hair dyes, patch tests are recommended to check for potential allergic reactions. This ingredient is regulated in various countries, with specific concentration limits set for its use in hair coloring products.