Ingredient review

5-Amino-6-Chloro-o-Cresol

INCI: 5-AMINO-6-CHLORO-O-CRESOL

A synthetic hair dye colorant that is generally safe when used as directed, but may cause irritation for sensitive individuals.

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In plain English

This is a synthetic ingredient used in permanent hair dyes to create certain colors, especially brown and warm tones. It works by reacting with other dye precursors inside the hair shaft to form larger color molecules that stay locked in. Because it's a chemical colorant, it can sometimes cause scalp irritation or allergic reactions, especially if you have sensitive skin or a history of hair dye allergies.

Quick decision guide

Read the cautions before using

5-Amino-6-Chloro-o-Cresol 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.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging 5-Amino-6-Chloro-o-Cresol.
  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

moderate

Can bother some users, especially with frequent use, damaged skin, or strong companion ingredients.

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

A synthetic aromatic compound belonging to the cresol family, used as a colorant in oxidative hair dye systems.

How it works

In oxidative hair dye, this ingredient acts as a coupler. It reacts with a primary intermediate (like p-phenylenediamine) in the presence of hydrogen peroxide to form colored molecules inside the hair cortex, producing a permanent color that resists washing.

Pros

Effective colorant

Helps achieve a broad spectrum of permanent hair colors, from natural browns to fashion shades, with good longevity.

Regulated use

Approved for use in hair dyes at controlled concentrations by major regulatory bodies, ensuring safety when used as directed.

Cons and cautions

Irritation potential

Can cause scalp irritation or allergic reactions, especially in individuals with sensitive skin or a history of contact dermatitis.

Not for all products

Restricted to rinse-off hair dye products; not safe for leave-on or skin-care applications due to sensitization risk.

Best for

  • People looking for permanent hair color with good gray coverage
  • Those who have used oxidative hair dyes without reaction

Use caution if

  • Individuals with known sensitivity or allergy to hair dye ingredients
  • Pregnant or nursing women who prefer to minimize chemical exposure

Usage tips

Always perform a patch test 48 hours before using any hair dye containing this ingredient.
Follow the manufacturer's instructions exactly, including recommended processing time and rinsing thoroughly.

Safety summary

Generally safe for its intended use as a hair dye ingredient when used at regulated concentrations. The main risk is allergic contact dermatitis, which can be mitigated by patch testing. Not intended for skin or leave-on use.

Research notes

The Cosmetic Ingredient Review (CIR) panel has evaluated related aminocresol compounds and found them safe for use in hair dyes at concentrations up to 1.5%. Individual sensitivity varies, and allergic reactions are possible.

Common label clues

Typical concentration
Up to 1.5% in ready-to-use hair dye products
Regulatory status
Approved for use in oxidative hair dyes in the EU (up to 1.5%) and regulated by the FDA as a color additive for hair dyes in the US. Always follow product instructions.
Common uses
Hair dye formulations
Environmental note
As a synthetic compound, it may persist in wastewater. Proper disposal of hair dye products is recommended to minimize environmental impact.

Good to know

  • This ingredient is often listed alongside other dye precursors like p-phenylenediamine (PPD) in permanent hair color boxes.
  • The European Cosmetics Regulation restricts its concentration to 1.5% in ready-to-use hair dye products.

Common questions

What is 5-Amino-6-Chloro-o-Cresol in beauty products?

This is a synthetic ingredient used in permanent hair dyes to create certain colors, especially brown and warm tones. It works by reacting with other dye precursors inside the hair shaft to form larger color molecules that stay locked in. Because it's a chemical colorant, it can sometimes cause scalp irritation or allergic reactions, especially if you have sensitive skin or a history of hair dye allergies.

What does 5-Amino-6-Chloro-o-Cresol do in a beauty product?

In oxidative hair dye, this ingredient acts as a coupler. It reacts with a primary intermediate (like p-phenylenediamine) in the presence of hydrogen peroxide to form colored molecules inside the hair cortex, producing a permanent color that resists washing.

Is 5-Amino-6-Chloro-o-Cresol safe for most people?

Generally safe for its intended use as a hair dye ingredient when used at regulated concentrations. The main risk is allergic contact dermatitis, which can be mitigated by patch testing. Not intended for skin or leave-on use.

Who should be careful with 5-Amino-6-Chloro-o-Cresol?

Individuals with known sensitivity or allergy to hair dye ingredients Pregnant or nursing women who prefer to minimize chemical exposure

Research sources

Cosmetic Ingredient Review (CIR) - Safety Assessment of AminocresolsOpenEuropean 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.