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Basic and cationic dyes

Neutral red

Also known as Toluylene Red, 3-Amino-7-dimethylamino-2-methylphenazine hydrochloride, C.I. Basic Red 5

CAS 553-24-2Formula C15H17ClN4Molar mass 288.78 g/molEC 209-035-8
GHS signal word: Warning. Pictograms: Harmful or irritant, Serious health hazard 69 suppliers listed
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Neutral red chemical structure, C15H17ClN4, CAS 553-24-2
2D chemical structure

Key facts

What buyers check first

All properties
CAS number
553-24-2
Formula
C15H17ClN4
Molar mass
288.78 g/mol
EC number
209-035-8
HS code
320413
Category
Basic and cationic dyes

What is Neutral red?

Plain description, key identifiers and synonyms

Neutral red is a hydrochloride obtained by combining the free base of neutral red with one equivalent of hydrochloric acid. Neutral red acts as a pH indicator, changing from red to yellow between pH 6.8 and 8.0. It has a role as a dye, an acid-base indicator and a two-colour indicator. It contains a neutral red(1+).

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
8-N,8-N,3-trimethylphenazine-2,8-diamine, hydrochloride
CAS number
553-24-2 CAS number cross-checkedOther or deprecated CAS: 150645-85-5
EC number
209-035-8
Molecular formula
C15H17ClN4
UNII
261QK3SSBH
MDL number
MFCD00012651
InChIKey
PGSADBUBUOPOJS-UHFFFAOYSA-N
InChI
InChI=1S/C15H16N4.ClH/c1-9-6-13-15(8-11(9)16)18-14-7-10(19(2)3)4-5-12(14)17-13;/h4-8H,16H2,1-3H3;1H
SMILES (canonical and isomeric)
CC1=CC2=NC3=C(C=C(C=C3)N(C)C)N=C2C=C1N.Cl

Synonyms

  • Toluylene Red
  • 3-Amino-7-dimethylamino-2-methylphenazine hydrochloride
  • C.I. Basic Red 5
  • Neutral Red chloride
  • Michrome No. 226
  • Neutral Red W
  • 2,8-Phenazinediamine, N8,N8,3-trimethyl-, monohydrochloride
  • C.I. 50040
  • Cerven neutralni
  • Cerven toluylenova
  • C.I. Basic Red 5, monohydrochloride
  • Cerven zasadita 5
  • Aminodimethylaminotoluaminozine hydrochloride
  • Nuclear Fast Red (basic dye)
  • Red, Toluylene
  • Red, Neutral
  • Kernechtrot
  • Basic Red 5
  • N2,N2,7-Trimethylphenazine-2,8-diamine hydrochloride
  • Neutral red,IND
  • Neutral Red (Technical Grade)
  • C.I. Basic Red 5, monohydrochloride (VAN)
  • Phenazine, 3-amino-7-(dimethylamino)-2-methyl-, hydrochloride
  • Phenazine, hydrochloride
  • Phenazine, monohydrochloride
Show all 34 synonyms
  • NeutralRed
  • 2, N8,N8,3-trimethyl-, monohydrochloride
  • Aminomethylaminotoluaminozine hydrochloride
  • Neutral
  • Neutral Red IND
  • Neutral Red, ACS
  • Neutral red indicator
  • N8,N8,3-Trimethyl-2,8-phenazinediamine monohydrochloride
  • Phenazine, 3-amino-7-(dimethylamino)-2-methyl-, monohydrochloride

Physical and chemical properties

Measured values and descriptors computed from the structure

Physical and chemical properties

Measured values, check the supplier specification for your grade

No measured properties are recorded for this substance yet. Ask suppliers for a technical data sheet.

Values vary by grade. Ask suppliers for the COA or TDS of the batch you buy.

Computed descriptors

Calculated from the structure, useful for screening and formulation

Molecular weight
288.78 g/molcalc.
Exact mass
288.1142 Dacalc.
LogP (octanol/water)
3.16calc.
Topological polar surface area
55.04 Ųcalc.
Hydrogen bond donors
1calc.
Hydrogen bond acceptors
4calc.
Rotatable bonds
1calc.
Heavy atoms
20calc.
Rings
3calc.
Aromatic rings
3calc.
Fraction sp3 carbons
0.2calc.
Formal charge
0calc.
Stereocentres
0calc.
Components
2calc.
Lipinski rule of five
Passes (0 violations)calc.

Calculated for screening. Confirm critical figures with the supplier.

Murcko scaffold

The ring system that remains when every side chain is removed

Murcko scaffold of this chemical, c1ccc2nc3ccccc3nc2c1

c1ccc2nc3ccccc3nc2c1

3 rings, 14 atoms, the Phenazine ring system.

364 other chemicals share this scaffold

Safety and hazards

GHS classification summary, not a safety data sheet

GHS signal word
Warning
GHS07: Harmful or irritant
Harmful or irritant
GHS08: Serious health hazard
Serious health hazard

Hazard statements

  • H315Causes skin irritation.
  • H319Causes serious eye irritation.
  • H335May cause respiratory irritation.
  • H341Suspected of causing genetic defects.
Precautionary statements (18)
  • P203Obtain, read and follow all safety instructions before use.
  • P261Avoid breathing dust, fume, gas, mist, vapours or spray.
  • P264Wash skin thoroughly after handling.
  • P264 + P265Wash skin thoroughly after handling. Do not touch eyes.
  • P271Use only outdoors or in a well-ventilated area.
  • P280Wear protective gloves, protective clothing, eye protection and face protection.
  • P302 + P352If on skin: Wash with plenty of water.
  • P304 + P340If inhaled: Remove person to fresh air and keep comfortable for breathing.
  • P305 + P351 + P338If in eyes: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • P318If exposed or concerned, get medical advice.
  • P319Get medical help if you feel unwell.
  • P321Specific treatment (see supplemental first aid instructions on the label).
  • P332 + P317If skin irritation occurs: Get medical help.
  • P337 + P317If eye irritation persists: Get medical help.
  • P362 + P364Take off contaminated clothing. And wash it before reuse.
  • P403 + P233Store in a well-ventilated place. Keep container tightly closed.
  • P405Store locked up.
  • P501Dispose of contents and container in accordance with local regulations.

GHS classification summary, not a safety data sheet (SDS). Classifications can differ by supplier, grade and concentration. Always check the supplier's SDS.

Full safety data and first aid

Neutral red suppliers

Sponsored listings first, then the documented ranking: membership, verification, replies, completeness, freshness and ratings

All 69 suppliers
30 of 30 offers

Suppliers marked Unclaimed profile have not claimed their profile yet. They are not verified by CompoundList, their offers are price on request and details may have changed, so please confirm them with the supplier. Company representatives can claim a profile with a business email on the company's own website domain. Our team verifies each claim and sends the result by email.

Where suppliers are based

69 suppliers in 12 countries

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Neutral red price

Indicative price range per kg from live supplier offers

No published prices right now

Suppliers quote this chemical on request. Send one free request and compare quotes side by side.

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Uses and applications

What the substance is used for, by industry and function

Pharmacological actions

  • Coloring Agents
  • Indicators and Reagents

Roles

  • acid-base indicator
  • colour indicator
  • dye
  • indicator
  • two-colour indicator
  • visual indicator

Regulatory status

Inventories, regulations and trade controls that list this substance

United States

  • TSCA inventory (USA)
    Status: Active in US commerce

HS code and trade data

Customs classification and reported world trade statistics

Global trade

World import and export statistics for the HS code Neutral red is traded under.

HS 3204.13Indicative HS code

Basic dyes and preparations based thereon

World exports in 2024
$209M
−2.6% vs 2023, imports $224M
2019 to 2024
Top exporters
  1. India * partner reported27.9%
  2. China21.8%
  3. Spain6.6%
Top importers
  1. United States11.2%
  2. China7.9%
  3. Germany7.4%

* Partner reported figures, a lower bound.

Reported customs values in USD, not prices.Full trade data

The HS code shown for Neutral red is indicative (it was assigned by structure rules). Confirm the classification with your customs broker before shipping.

Frequently asked questions

Quick answers about Neutral red, based on the data on this page

What is Neutral red?

Neutral red is a hydrochloride obtained by combining the free base of neutral red with one equivalent of hydrochloric acid. Neutral red acts as a pH indicator, changing from red to yellow between pH 6.8 and 8.0. It has a role as a dye, an acid-base indicator and a two-colour indicator. It contains a neutral red(1+).

What is the CAS number of Neutral red?

The CAS registry number of Neutral red is 553-24-2. Other or deprecated CAS numbers: 150645-85-5.

What is the molecular formula and weight of Neutral red?

The molecular formula of Neutral red is C15H17ClN4 and its molar mass is 288.78 g/mol.

What is Neutral red used for?

Known uses and roles of Neutral red include textile dyes in textiles and leather, indicators and stains in research and laboratory, acid-base indicator, colour indicator, dye and 5 more.

Is Neutral red hazardous?

Neutral red carries the GHS signal word "Warning". Main hazards: causes skin irritation, causes serious eye irritation, may cause respiratory irritation. This summary is not an SDS, always read the supplier safety data sheet.

What is the HS code of Neutral red?

Neutral red is usually classified under HS code 320413 (Basic dyes and preparations based thereon). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Neutral red?

CompoundList lists 69 suppliers of Neutral red in United States, China, India, United Kingdom and 8 more. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

Where can I buy Neutral red in India?

12 suppliers in India list Neutral red on CompoundList. Filter the suppliers list by country and send a request to compare prices, grades and delivery times.

What is the price of Neutral red?

Suppliers quote Neutral red on request because prices depend on grade, purity, quantity and destination. A free request on CompoundList gets you several quotes to compare.

Guides for buyers

Practical guides that help when you source, ship or handle Neutral red

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Data last updated 7 Oct 2026. Details may have changed, please confirm them with the supplier. Report an error on this page
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