Ingredient review

2-Hydroxyethylamino-5-Nitroanisole

INCI: 2-HYDROXYETHYLAMINO-5-NITROANISOLE

A synthetic hair dye that provides blue-violet tones but may cause skin irritation in sensitive individuals.

beautyhair colorsynthetic dye

In plain English

This is a man-made color molecule used in hair dye to create blue or violet shades. It works by depositing color onto the outer layer of your hair strands. Because it's a small molecule, it can sometimes penetrate the skin and cause irritation, especially if you have sensitive skin or a history of allergic reactions to hair dye.

Quick decision guide

Read the cautions before using

2-Hydroxyethylamino-5-Nitroanisole 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 2-Hydroxyethylamino-5-Nitroanisole.
  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 organic compound belonging to the nitroaniline dye family, used as a colorant in cosmetic hair products.

How it works

In a hair dye product, this molecule binds to the hair shaft's outer cuticle, depositing color that lasts through several washes. It does not chemically alter the hair structure like permanent dyes do, so the color fades gradually.

Pros

Vibrant color payoff

Delivers intense blue-violet shades that are hard to achieve with natural dyes.

Semi-permanent formula

Color gradually washes out over several shampoos, reducing the need for harsh removal processes.

Cons and cautions

Skin irritation risk

Can cause redness, itching, or swelling on the scalp or skin, especially with repeated use.

Limited safety data

Long-term safety studies on this specific dye are not as extensive as for some other hair colorants.

Best for

  • People looking for temporary blue or violet hair color
  • Those who have used similar nitro dyes without reaction

Use caution if

  • Individuals with known sensitivity or allergy to hair dyes
  • People with damaged or compromised scalp skin

Usage tips

Always perform a patch test 48 hours before using any product containing this dye.
Wear gloves during application to minimize skin contact.
Rinse thoroughly after the recommended processing time to reduce residue on the scalp.

Safety summary

Generally considered safe for use in rinse-off hair color products at low concentrations, but carries a moderate risk of skin irritation and allergic reactions. Patch testing is strongly advised.

Research notes

Moderate evidence supports its use as a hair colorant, with some studies indicating potential for sensitization. More long-term exposure data would strengthen the safety profile.

Common label clues

Typical concentration
0.1% to 2.0% in rinse-off hair color products
Regulatory status
Approved for use in hair dye products in the EU and US within specified concentration limits, but subject to labeling requirements for potential allergens.
Common uses
Semi-permanent hair dyes, Temporary hair color products
Environmental note
Synthetic dyes can persist in wastewater; proper disposal of unused product is recommended to minimize environmental impact.

Good to know

  • This ingredient is often listed as HC Blue No. 2 on product labels.
  • It is not approved for use in all countries; check local regulations if you are outside the US or EU.

Common questions

What is 2-Hydroxyethylamino-5-Nitroanisole in beauty products?

This is a man-made color molecule used in hair dye to create blue or violet shades. It works by depositing color onto the outer layer of your hair strands. Because it's a small molecule, it can sometimes penetrate the skin and cause irritation, especially if you have sensitive skin or a history of allergic reactions to hair dye.

What does 2-Hydroxyethylamino-5-Nitroanisole do in a beauty product?

In a hair dye product, this molecule binds to the hair shaft's outer cuticle, depositing color that lasts through several washes. It does not chemically alter the hair structure like permanent dyes do, so the color fades gradually.

Is 2-Hydroxyethylamino-5-Nitroanisole safe for most people?

Generally considered safe for use in rinse-off hair color products at low concentrations, but carries a moderate risk of skin irritation and allergic reactions. Patch testing is strongly advised.

Who should be careful with 2-Hydroxyethylamino-5-Nitroanisole?

Individuals with known sensitivity or allergy to hair dyes People with damaged or compromised scalp skin

Research sources

European Chemicals Agency (ECHA) - 2-Hydroxyethylamino-5-NitroanisoleOpenCosmetic Ingredient Review (CIR) - Safety Assessment of Nitroaniline DyesOpenPubMed - Contact allergy to hair dyesOpen

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.