Ingredient review
HC Blue No. 13
INCI: HC Blue No. 13
HC Blue No. 13 is a synthetic blue dye for hair color, generally considered safe in rinse-off products but may cause irritation in sensitive individuals.
In plain English
HC Blue No. 13 is a man-made blue colorant used in hair dyes. It belongs to a group of dyes called HC (Hair Color) dyes that deposit color onto the hair shaft without needing a developer. Because it's a synthetic chemical, it can sometimes cause skin irritation, especially on sensitive scalps or with repeated use. It is not used in skincare or leave-on products.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Main practical flags: irritation is moderate; clogging risk is low.
- Source
- synthetic
- Evidence
- moderate
- Irritation
- moderate
- Clogging risk
- low
Quick decision guide
Useful, but context matters
HC Blue No. 13 can be useful, but watch for some irritation potential.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging HC Blue No. 13.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- 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
moderateCan bother some users, especially with frequent use, damaged skin, or strong companion ingredients.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
HC Blue No. 13 is a synthetic anthraquinone dye specifically designed for coloring hair. It is a blue powder that is soluble in water and alcohol, allowing it to be incorporated into liquid or cream hair color bases.
How it works
In a hair color product, HC Blue No. 13 molecules are small enough to penetrate the outer cuticle layer of the hair. Once inside, they become trapped, imparting a blue tint. Because it does not require an oxidizing agent like hydrogen peroxide, the color is semi-permanent and gradually washes out over several shampoos.
Pros
Vibrant color payoff
HC Blue No. 13 delivers a strong blue hue that can be used alone or blended with other dyes for custom shades.
Semi-permanent flexibility
Because it doesn't require a developer, the color fades gradually over 4-8 washes, making it ideal for temporary color experiments.
Cons and cautions
Potential scalp irritation
As a synthetic dye, it can cause contact dermatitis or itching in people with sensitive skin, especially during prolonged application.
Staining risk
The dye can stain skin, towels, and clothing if not handled carefully, and may require extra cleanup.
Best for
- People looking for semi-permanent blue hair color
- Those who want to avoid permanent dyes with ammonia or peroxide
Use caution if
- Individuals with known sensitivity or allergy to synthetic hair dyes
- People with damaged or porous hair that may absorb dye unevenly
Usage tips
Safety summary
HC Blue No. 13 is considered safe for use in rinse-off hair dyes at typical concentrations. However, it can cause skin irritation or allergic reactions in some individuals. Regulatory bodies restrict its use to hair products only.
Research notes
Studies on HC Blue No. 13 are limited, but it is part of a class of HC dyes that have been evaluated for skin sensitization and genotoxicity. The Cosmetic Ingredient Review (CIR) panel has reviewed similar HC dyes and found them safe for rinse-off use at low concentrations.
Common label clues
- Typical concentration
- Typically used at 0.1% to 2% in hair color products
- Regulatory status
- Approved for use in rinse-off hair color products in the EU (Annex III) and by the US FDA as a color additive for hair dyes. Not permitted in leave-on cosmetics or skincare.
- Common uses
- Semi-permanent hair dyes, Temporary hair rinses
- Environmental note
- Synthetic dyes like HC Blue No. 13 are not biodegradable and may accumulate in wastewater. Proper disposal of hair color products is recommended to minimize environmental impact.
Good to know
- HC Blue No. 13 is approved for use in hair dyes in the EU and US, but is not permitted in leave-on cosmetics.
- It is often combined with other HC dyes to achieve a range of blue, purple, or green shades.
Common questions
What is HC Blue No. 13 in beauty products?
HC Blue No. 13 is a man-made blue colorant used in hair dyes. It belongs to a group of dyes called HC (Hair Color) dyes that deposit color onto the hair shaft without needing a developer. Because it's a synthetic chemical, it can sometimes cause skin irritation, especially on sensitive scalps or with repeated use. It is not used in skincare or leave-on products.
What does HC Blue No. 13 do in a beauty product?
In a hair color product, HC Blue No. 13 molecules are small enough to penetrate the outer cuticle layer of the hair. Once inside, they become trapped, imparting a blue tint. Because it does not require an oxidizing agent like hydrogen peroxide, the color is semi-permanent and gradually washes out over several shampoos.
Is HC Blue No. 13 safe for most people?
HC Blue No. 13 is considered safe for use in rinse-off hair dyes at typical concentrations. However, it can cause skin irritation or allergic reactions in some individuals. Regulatory bodies restrict its use to hair products only.
Who should be careful with HC Blue No. 13?
Individuals with known sensitivity or allergy to synthetic hair dyes People with damaged or porous hair that may absorb dye unevenly
Research sources
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.