Back to Ingredient Dictionary

HC RED NO. 1

Description

HC Red No. 1, also known as 4-amino-2-nitrophenol, is a synthetic hair dye ingredient primarily used in semi-permanent and temporary hair coloring products. This compound imparts a vibrant red hue to hair and is often combined with other dyes to create various shades of red, burgundy, and auburn. HC Red No. 1 is classified as a nitro dye, which means it contains a nitro group in its chemical structure.

This dye penetrates the hair shaft without the need for an oxidizing agent, making it less damaging compared to permanent hair dyes. It typically lasts for 4-6 washes, gradually fading with each shampoo. HC Red No. 1 is particularly effective on pre-lightened or naturally light hair but may also provide a tinting effect on darker hair.

While HC Red No. 1 is approved for use in hair dyes in many countries, it's important to note that some regulatory bodies have restricted its concentration due to potential skin sensitization concerns. As with all hair dyes, a patch test is recommended before use to check for any adverse reactions. Professional application and following manufacturer instructions can help minimize risks associated with this ingredient.