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Fluorescent dyes and stains

Eosin

Also known as Acid red 87, Eosin yellowish, Eosine Yellowish

CAS 17372-87-1Formula C20H6Br4Na2O5Molar mass 691.86 g/molEC 241-409-6
GHS signal word: Warning. Pictograms: Harmful or irritant 83 suppliers listed
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Eosin chemical structure, C20H6Br4Na2O5, CAS 17372-87-1
2D chemical structure

Key facts

What buyers check first

All properties
Physical form
Powder
Melting point
300 °C
Solubility
Greater than or equal to 100 mg/mL at 70 °F
HS code
320412
Category
Fluorescent dyes and stains
Illustrative photo, 25 kg white woven sacks of powder on a pallet in a warehouse
Typical packagingIllustrative packaging image, not the actual product

What is Eosin?

Plain description, key identifiers and synonyms

Eosin YS dye is an organic sodium salt that is 2',4',5',7'-tetrabromofluorescein in which the carboxy group and the phenolic hydroxy group have been deprotonated and the resulting charge is neutralised by two sodium ions. It has a role as a fluorochrome and a histological dye. It is an organobromine compound and an organic sodium salt. It contains a 2',4',5',7'-tetrabromofluorescein(2-).

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
disodium, 2-(2,4,5,7-tetrabromo-3-oxido-6-oxoxanthen-9-yl)benzoate
CAS number
17372-87-1 CAS number cross-checkedOther or deprecated CAS: 125399-78-2, 548-26-5
EC numbers
241-409-6, 611-203-4
Molecular formula
C20H6Br4Na2O5
UNII
TDQ283MPCW
INCI name
ACID RED 87, CI 45380
InChIKey
SEACYXSIPDVVMV-UHFFFAOYSA-L
InChI
InChI=1S/C20H8Br4O5.2Na/c21-11-5-9-13(7-3-1-2-4-8(7)20(27)28)10-6-12(22)17(26)15(24)19(10)29-18(9)14(23)16(11)25;;/h1-6,25H,(H,27,28);;/q;2*+1/p-2
SMILES (canonical and isomeric)
C1=CC=C(C(=C1)C2=C3C=C(C(=O)C(=C3OC4=C(C(=C(C=C24)Br)[O-])Br)Br)Br)C(=O)[O-].[Na+].[Na+]

Synonyms

  • Acid red 87
  • Eosin yellowish
  • Eosine Yellowish
  • Eosine
  • Eosine G
  • Eosin YS
  • Sodium eosine
  • Bromo acid
  • Eosine Y
  • Bromofluorescein
  • Sodium eosinate
  • Bronze Bromo
  • Certiqual Eosine
  • Bromo Fluorescein
  • Eosine A
  • Eosine J
  • Eosine BS
  • Eosine DA
  • Eosine FA
  • Eosine GF
  • Eosine OJ
  • Eosine w/s
  • Eosine YB
  • Eosine YS
  • Toyo Eosine G
Show all 39 synonyms
  • Bromo B
  • Eosine BPC
  • Eosine Salt Free
  • Pure Eosine YY
  • Bromo FL
  • Bromo TS
  • Bromo XX
  • Bromo JPS
  • Eosine 3G
  • Eosine 3Y
  • Eosine BS-SF
  • Bromo 4DC
  • Hidacid White Bromo
  • Symuler Eosin Toner

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

Physical form
Powderexp.
Melting point
300 °Cexp.
Solubility
Greater than or equal to 100 mg/mL at 70 °Fexp.

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
691.86 g/molcalc.
Exact mass
687.6744 Dacalc.
LogP (octanol/water)
-0.94calc.
Topological polar surface area
93.4 Ųcalc.
Hydrogen bond donors
0calc.
Hydrogen bond acceptors
5calc.
Rotatable bonds
2calc.
Heavy atoms
31calc.
Rings
4calc.
Aromatic rings
2calc.
Fraction sp3 carbons
0calc.
Formal charge
0calc.
Stereocentres
0calc.
Components
3calc.
Lipinski rule of five
Passes (1 violation)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, O=c1ccc2c(-c3ccccc3)c3ccccc3oc-2c1

O=c1ccc2c(-c3ccccc3)c3ccccc3oc-2c1

4 rings, 21 atoms.

166 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

Hazard statements

  • H319Causes serious eye irritation.
Precautionary statements (4)
  • P264 + P265Wash skin thoroughly after handling. Do not touch eyes.
  • P280Wear protective gloves, protective clothing, eye protection and face protection.
  • P305 + P351 + P338If in eyes: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • P337 + P317If eye irritation persists: Get medical help.

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

Eosin suppliers

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

All 83 suppliers
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Where suppliers are based

83 suppliers in 15 countries

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Eosin price

Indicative price range per kg from live supplier offers

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Uses and applications

What the substance is used for, by industry and function

Use classes: Cosmetics.

Cosmetic ingredient, INCI name ACID RED 87(colorant, hair dyeing)

Pharmacological actions

  • Fluorescent Dyes

Roles

  • dye
  • fluorescent dye
  • fluorochrome
  • histological dye

Functional uses

  • Dye

Cosmetic functions

  • Colorant
  • Hair dyeing

Regulatory status

Inventories, regulations and trade controls that list this substance

Health and food

  • EU cosmetic ingredient inventory
  • EU Cosmetics Regulation Annex IV, allowed colourant
    Name: CI 45380 / ACID RED 87, Ref no: 76, Annex ref: IV/76

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 Eosin is traded under.

HS 3204.12Indicative HS code

Acid dyes, whether or not premetallised, and preparations based thereon, mordant dyes…

World exports in 2024
$792M
+6.2% vs 2023, imports $791M
2019 to 2024
Top exporters
  1. India * partner reported34.9%
  2. China9.3%
  3. Germany7.4%
Top importers
  1. China15.3%
  2. Italy8.2%
  3. United States7.3%

* Partner reported figures, a lower bound.

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

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

Frequently asked questions

Quick answers about Eosin, based on the data on this page

What is Eosin?

Eosin YS dye is an organic sodium salt that is 2',4',5',7'-tetrabromofluorescein in which the carboxy group and the phenolic hydroxy group have been deprotonated and the resulting charge is neutralised by two sodium ions. It has a role as a fluorochrome and a histological dye.

What is the CAS number of Eosin?

The CAS registry number of Eosin is 17372-87-1. Other or deprecated CAS numbers: 125399-78-2, 548-26-5.

What is the molecular formula and weight of Eosin?

The molecular formula of Eosin is C20H6Br4Na2O5 and its molar mass is 691.86 g/mol.

What is Eosin used for?

Use classes: Cosmetics.

Is Eosin hazardous?

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

What is the HS code of Eosin?

Eosin is usually classified under HS code 320412 (Acid dyes, whether or not premetallised, and preparations based thereon, mordant dyes…). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Eosin?

CompoundList lists 83 suppliers of Eosin in United States, China, India, United Kingdom and 11 more. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

Where can I buy Eosin in India?

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

What is the price of Eosin?

Suppliers quote Eosin 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 Eosin

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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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