Molekula
Eosin Y (C.I. 45380)
Supplying 4,500+ customers in over 80 countries
ISO 9001:2015 & ISO 14001:2015 certified · Supplying laboratories and industry since 1999 · Listed pack sizes are a starting point — we manufacture, source and repack to the quantity you need
Eosin Y (C.I. 45380) is a synthetic fluorescent dye belonging to the xanthene family, widely used as a biological stain in microscopy, histology, and microbiology for differentiating cellular structures. It is also employed as a colorant in cosmetics (as D&C Red No. 22), in ink production, and as a photosensitizer in photodynamic therapy. This chemical has a CAS number of 17372-87-1, a molecular formula of C20H6Br4Na2O5, and a molecular weight of 691.85. It should be stored at ambient conditions, with a signal word of Warning indicating moderate hazard.
Molekula supplies Eosin Y (C.I. 45380) in 5 g to 250 g packs, from £13.20 inc. VAT. It is in stock for same-day dispatch. Every batch ships with a certificate of analysis, and safety data sheets are available in 6 languages. Larger quantities, up to multi-tonne, are quoted on request.
Example image for illustration only. Other packaging and pack sizes are available.
Often bought together
Pricing & pack sizes
In stock — same-day dispatch
These pack sizes aren't a limit. Molekula manufactures, sources and repacks to order — if you need 500 kg and only see 1 kg listed, . We quote from grams to multi-tonne.
Need a different size? Add the nearest pack and change the size in your basket — we price it at the same rate per unit.
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5 g — £11.00 per pack ex VAT · £13.20 inc. VAT
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25 g — £21.70 per pack ex VAT · £26.04 inc. VAT
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50 g — £38.00 per pack ex VAT · £45.60 inc. VAT
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100 g — £51.00 per pack ex VAT · £61.20 inc. VAT
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250 g — £81.00 per pack ex VAT · £97.20 inc. VAT
Need a different quantity or pack?
Tell us how much you need and when — drums, IBCs, sacks or a one-off bulk lot. We'll manufacture or source it and come back with a price.
Prices exclude VAT/sales tax and shipping.
Specifications
| Property | Value |
|---|---|
| Appearance | Rust red powder |
| Loss on Drying | ≤ 5.0% |
| Dye Content | ≥ 90.0% |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Acidity | Neutral |
Literature values
Published physical properties of the substance, not batch specifications.
| Property | Value |
|---|---|
| Melting Point | 300 °C (decomposes) |
Source: PubChem CID 11048 (CAMEO Chemicals)
Identification
| Property | Value |
|---|---|
| SKU | 31787521 |
| CAS Number | 17372-87-1 |
| IUPAC Name | disodium;2-(2,4,5,7-tetrabromo-3-oxido-6-oxoxanthen-9-yl)benzoate |
| EC Number | 241-409-6 |
| Molecular Formula | C20H6Br4Na2O5 |
| Molecular Weight | 691.85 |
| Exact Mass | 691.6703 |
| SMILES | 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+] |
| 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 |
| PubChem CID | 11048 |
| REACH Code | Y110 |
| TSCA Listed | Yes |
| HTS Code | 32129000 |
| Tariff Code | 3212900000 |
Safety & GHS
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Health Hazard
GHS07
Hazard statements
- H303 May be harmful if swallowed
- H317 May cause an allergic skin reaction
- H319 Causes serious eye irritation
Precautionary statements
- P261 Avoid breathing dust/fume/gas/mist/vapours/spray
- P280 Wear protective gloves/protective clothing/eye protection/face protection
- P302+352 IF ON SKIN: Wash with soap and water
- P305+351+338 IF IN EYES: Rinse with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing
Documents
Safety Data Sheets (SDS)
Available in English, French, German, Italian, Russian, Spanish.
Certificate of Analysis (CoA) by batch
Enter a lot or batch number to retrieve the CoA for that specific batch. We can generate one from spec data if no PDF is on file.
Quality certificates
Molekula Group is certified to ISO 9001:2015 (quality) and ISO 14001:2015 (environmental management), audited by a UKAS-accredited body. Both certificates are valid to 17 May 2028.
Synonyms
- Acid red 87
- Bromo acid
- Eosin
- Eosin yellowish
- Eosin YS
- Eosine
- Eosine G
- Eosine Y
- Eosine Yellowish
- Sodium eosine
Frequently asked questions
What is Eosin Y (C.I. 45380) commonly used for?
Eosin Y is primarily used as a fluorescent dye in biological and medical staining, microscopy, and as a photosensitizer in photodynamic therapy.
What is the chemical formula and molecular weight of Eosin Y?
The chemical formula is C₂₀H₆Br₄Na₂O₅, and the molecular weight is 691.85 g/mol.
How should Eosin Y be stored?
Store Eosin Y at ambient temperature in a cool, dry place, away from direct sunlight and incompatible substances.
What grades or purity levels of Eosin Y does Molekula supply?
Molekula supplies Eosin Y as a rust red powder with a dye content of at least 90.0% and loss on drying of no more than 5.0%, suitable for research and industrial applications.
Can Molekula supply Eosin Y in bulk quantities?
Yes, Molekula can provide Eosin Y in bulk, with quantities tailored to your specific requirements—please contact us for details.
What documentation comes with an order of Eosin Y?
Each order includes a Certificate of Analysis (CoA), Material Safety Data Sheet (MSDS), and batch-specific documentation for traceability.
Where can I buy Eosin Y (C.I. 45380)?
Directly from Molekula, which lists Eosin Y (C.I. 45380) in 5 g to 250 g packs from £13.20 inc. VAT, with a certificate of analysis for every batch. Larger quantities are quoted on request. Molekula's offices: United Kingdom, France, Spain, Germany, Italy, United States and China.
Ready to order or need a custom pack?
Tell us the product, grade, and quantity — Molekula usually responds within one working day with pricing and lead time.