Ingredient review

Basic Blue 124

INCI: Basic Blue 124

Basic Blue 124 is a synthetic blue dye that adds color to products but offers no skincare benefits; it is generally considered safe in low concentrations for most people.

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In plain English

Basic Blue 124 is a man-made blue pigment used to make shampoos, conditioners, and other rinse-off products look a certain color. It doesn't do anything for your skin or hair—it's purely cosmetic. In the tiny amounts used, it's unlikely to cause problems for most people, but those with very sensitive skin or allergies to dyes might want to avoid it.

Quick decision guide

Read the cautions before using

Basic Blue 124 is generally a lower-concern ingredient when the full formula suits your skin.

Plain-English read

Treat this as a practical screening step before you compare products that contain this ingredient.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging Basic Blue 124.
  2. Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
  3. Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.

Score terms in plain English

Irritation risk

low

Less likely to sting, burn, or bother most users, though sensitive skin can still react.

Clogging risk

low

Less likely to feel heavy or contribute to clogged pores for most skin types.

Evidence level

moderate

There is useful support, but formula details and claim strength still matter.

What it is

Basic Blue 124 is a synthetic cationic dye from the triarylmethane family, used to give a blue hue to cosmetic products. It is listed as CI 11111 in the Color Index.

How it works

It works by absorbing and reflecting light in the blue spectrum, making the product appear blue. It does not interact with skin or hair biologically.

Pros

Vibrant color

Gives a bright, stable blue shade to shampoos and conditioners, making them visually appealing.

Low risk for most

At typical low concentrations, it is unlikely to cause irritation or clog pores for the majority of users.

Cons and cautions

No skincare benefit

This ingredient is purely cosmetic and does not moisturize, protect, or improve skin or hair health.

Potential allergen

Some people may experience contact dermatitis or allergic reactions, especially with prolonged exposure or in leave-on products.

Best for

  • People who enjoy colorful rinse-off products
  • Those without known dye allergies

Use caution if

  • Individuals with known sensitivity to synthetic dyes
  • People with very sensitive or reactive skin

Usage tips

Use in rinse-off products only to minimize skin contact time.
Patch test if you have a history of reactions to hair dyes or colored cosmetics.

Safety summary

Basic Blue 124 is considered safe for use in rinse-off cosmetics at low concentrations by major regulatory bodies, but it may cause irritation or allergic reactions in sensitive individuals.

Research notes

Limited peer-reviewed research exists specifically on Basic Blue 124, but it is grouped with other triarylmethane dyes that have been reviewed for safety in cosmetics by the Cosmetic Ingredient Review (CIR) panel.

Common label clues

Typical concentration
Very low, typically less than 1%
Regulatory status
Approved for use in rinse-off cosmetics in the EU and US at low concentrations, but not typically allowed in leave-on products near eyes or mucous membranes.
Common uses
Shampoos, Conditioners, Hair dyes, Soaps
Environmental note
Synthetic dyes can persist in water systems; proper disposal and wastewater treatment are important to minimize environmental impact.

Good to know

  • Basic Blue 124 is often listed under its Color Index number CI 11111 on ingredient labels.
  • It is not approved for use in leave-on products in some regions due to higher irritation potential.

Common questions

What is Basic Blue 124 in beauty products?

Basic Blue 124 is a man-made blue pigment used to make shampoos, conditioners, and other rinse-off products look a certain color. It doesn't do anything for your skin or hair—it's purely cosmetic. In the tiny amounts used, it's unlikely to cause problems for most people, but those with very sensitive skin or allergies to dyes might want to avoid it.

What does Basic Blue 124 do in a beauty product?

It works by absorbing and reflecting light in the blue spectrum, making the product appear blue. It does not interact with skin or hair biologically.

Is Basic Blue 124 safe for most people?

Basic Blue 124 is considered safe for use in rinse-off cosmetics at low concentrations by major regulatory bodies, but it may cause irritation or allergic reactions in sensitive individuals.

Who should be careful with Basic Blue 124?

Individuals with known sensitivity to synthetic dyes People with very sensitive or reactive skin

Research sources

Cosmetic Ingredient Review (CIR) - Triarylmethane DyesOpenEuropean Commission CosIng DatabaseOpen

Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.