Ingredient review

2-Nitro-5-Glyceryl Methylaniline

INCI: 2-NITRO-5-GLYCERYL METHYLANILINE

A synthetic blue dye used in hair color; generally safe for most people but may cause irritation in sensitive individuals.

beautyhair colorsynthetic dye

In plain English

This is a man-made blue dye that's added to hair color products to give your hair a blue tint. It's not a moisturizer or treatment—it's purely for color. Because it's a dye, it can sometimes cause skin irritation, especially if you have sensitive skin or a history of allergic reactions to hair color.

Quick decision guide

Useful, but context matters

2-Nitro-5-Glyceryl Methylaniline 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-Nitro-5-Glyceryl Methylaniline.
  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 that belongs to the nitroaniline family, used as a colorant in hair dyes to produce blue shades.

How it works

It deposits color onto the hair shaft by binding to the hair's outer layer (cuticle). In oxidative hair dyes, it reacts with other ingredients to form larger color molecules that get trapped inside the hair, providing longer-lasting color.

Pros

Vibrant color

Delivers a true blue shade that can be used alone or mixed with other dyes for custom tones.

Versatile use

Works in both temporary and semi-permanent hair color formulas, giving you flexibility in how long the color lasts.

Cons and cautions

Irritation risk

Can cause skin irritation or allergic reactions, especially if you have sensitive skin or a history of dye allergies.

Not for brows or lashes

This ingredient is not approved for use near the eyes, so it should never be used on eyebrows or eyelashes.

Best for

  • People looking for blue hair color in a salon or at-home dye
  • Those without known sensitivity to hair dyes

Use caution if

  • Individuals with a known allergy to para-phenylenediamine (PPD) or other hair dye ingredients
  • People with sensitive or irritated scalps

Usage tips

Always perform a patch test 48 hours before using any hair dye containing this ingredient.
Wear gloves when applying the dye to avoid staining your hands.
Rinse thoroughly after the recommended processing time to minimize skin contact.

Safety summary

Generally considered safe for use in hair dyes at regulated concentrations. However, it can cause skin irritation or allergic reactions in sensitive individuals. Always patch test before use.

Research notes

Limited peer-reviewed studies specifically on this ingredient, but it is part of a class of nitroaniline dyes that have been evaluated by cosmetic safety panels. The EU Scientific Committee on Consumer Safety (SCCS) has reviewed similar dyes and found them safe at low concentrations in rinse-off hair products.

Common label clues

Typical concentration
Up to 1.5% in rinse-off hair products
Regulatory status
Approved for use in hair dyes in the EU and US at concentrations up to 1.5% in rinse-off products. Not approved for use in products applied to the eye area.
Common uses
Hair dyes, Temporary and semi-permanent hair color
Environmental note
As a synthetic dye, it may not be biodegradable. Proper disposal of hair dye wastewater is recommended to minimize environmental impact.

Good to know

  • This ingredient is also known as HC Blue No. 12 in some product listings.
  • It is not a natural ingredient—it's fully synthetic and designed specifically for hair color.

Common questions

What is 2-Nitro-5-Glyceryl Methylaniline in beauty products?

This is a man-made blue dye that's added to hair color products to give your hair a blue tint. It's not a moisturizer or treatment—it's purely for color. Because it's a dye, it can sometimes cause skin irritation, especially if you have sensitive skin or a history of allergic reactions to hair color.

What does 2-Nitro-5-Glyceryl Methylaniline do in a beauty product?

It deposits color onto the hair shaft by binding to the hair's outer layer (cuticle). In oxidative hair dyes, it reacts with other ingredients to form larger color molecules that get trapped inside the hair, providing longer-lasting color.

Is 2-Nitro-5-Glyceryl Methylaniline safe for most people?

Generally considered safe for use in hair dyes at regulated concentrations. However, it can cause skin irritation or allergic reactions in sensitive individuals. Always patch test before use.

Who should be careful with 2-Nitro-5-Glyceryl Methylaniline?

Individuals with a known allergy to para-phenylenediamine (PPD) or other hair dye ingredients People with sensitive or irritated scalps

Research sources

EU CosIng DatabaseOpenFDA Cosmetics InformationOpenSCCS Opinion on 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.