Basic Blue 99

What is Basic Blue 99?

Basic Blue 99, also known as CI 61565, is a synthetic cationic azo dye characterized by its quaternary ammonium structure and vibrant blue hue. Developed for cosmetic applications, it belongs to the class of basic dyes that are water-soluble and intensely colored. Primarily utilized in hair care products like semi-permanent dyes, toners, and color-depositing shampoos, it functions as a direct colorant. This means it adheres directly to the hair shaft through electrostatic attraction to negatively charged keratin proteins, without requiring chemical oxidation. The dye provides immediate color payoff, blending well in formulations to achieve shades from deep blue to turquoise, while fading gradually with washes for non-committal coloring.

Comedogenic Rating 0/5 Low risk of clogging pores
EWG Safety Rating 3 View on EWG →
PubChem View on PubChem →

Roles in Formulation

This ingredient serves the following purposes in cosmetic formulations:

Hair colorant
Delivers hair color through dyes and/or pigments (direct or oxidative systems), producing a visible shade change and supporting coverage and longevity.
Hair dyeing
Supports chemical color change of hair (e.g., oxidative dye development or bleaching), enabling shade transformation through controlled reactions on the fiber.

Benefits

Delivers intense blue pigmentation for customized hair shades.

Supports even color deposit on hair fibers for natural-looking results.

Offers temporary coloring that washes out over time, allowing experimentation.

Who It's For

A quick guide for who this ingredient may suit (and who should be cautious).

Who May Benefit Who Should Avoid
Individuals seeking vibrant, non-permanent blue hair tones.
Those with known allergies to hair dye ingredients.
People wanting to refresh faded color-treated hair.
People experiencing scalp sensitivity or irritation from dyes.
Users of semi-permanent dyes for low-commitment style changes.
Individuals prone to contact dermatitis from synthetic colorants.

Safety Notes

  • Rated moderate concern by EWG, with low comedogenic potential.
  • Typically used in rinse-off hair products to minimize exposure.

Frequently Asked Questions about Basic Blue 99

What is Basic Blue 99 used for?

It serves as a hair colorant in semi-permanent dyes and toners to impart blue shades.

Is Basic Blue 99 comedogenic?

It has a comedogenic rating of 0, indicating no pore-clogging potential.

Does it require oxidation to work?

No, it functions as a direct dye, applying color without chemical reactions.