Description

Acid Red 51 is a synthetic, water-soluble xanthene dye widely recognized for its vibrant red color. It is a critical component for imparting stable and intense coloration in a variety of industrial and consumer applications. This high-purity dye is essential for manufacturers in the cosmetics, pharmaceutical, and food industries seeking reliable and compliant colorants. Acid Red 51 CAS NO 1342-25-2 is supplied under stringent quality control to ensure batch-to-batch consistency.

Application

• Cosmetic Colorant: Used in lipsticks, blushes, nail polishes, and other makeup products for its bright red hue.
• Food Coloring (where approved): Employed as a color additive in certain foodstuffs, beverages, and confectionery.
• Pharmaceutical Dye: Utilized for coloring tablets, capsules, and topical ointments for product identification.
• Biological Staining: Serves as a histological stain in laboratory settings for microscopic analysis.
• Inkjet Inks: A key pigment for producing red inks in industrial and specialty printing applications.
• Textile Dyeing: Applied for dyeing silk, wool, and nylon fibers.
• Paper Coloring: Used to impart color to specialty papers and cardboard products.
• Indicator Chemistry: Can function as a pH indicator in certain analytical and educational contexts.

Basic Information

Product Name	Acid Red 51
CAS No.	1342-25-2
Molecular Formula	C₂₀H₂Br₂N₂Na₂O₉
Molecular Weight	692.09 g/mol
Synonyms	Eosin Y; Eosin Yellowish; Acid Red 87; C.I. 45380; Bromoeosin; 2',4',5',7'-Tetrabromofluorescein disodium salt; Eosin Y, water soluble; Eosin Yellow
EINECS	215-691-6

Quality Control

Our Acid Red 51 is manufactured under a GMP-compliant quality management system to ensure the highest standards of purity and safety. Each batch is rigorously tested against stringent in-house specifications, which may include parameters for heavy metals, residual solvents, and dye content. Certificates of Analysis (COA) documenting identity, purity, and conformance are available for every shipment. We support compliance with relevant regulations such as FDA (where applicable), EU Cosmetics Regulation, and REACH.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at a controlled room temperature (15-25°C). Keep the container tightly sealed when not in use to protect from moisture.

Specification

Item	Specification
Appearance	Red to brownish-red powder
Identification (IR)	Conforms to standard
Assay (HPLC)	≥ 85.0% (as dye content)
Loss on Drying	≤ 10.0 %
Residue on Ignition (Sulfated Ash)	≤ 30.0 %
Heavy Metals (as Pb)	≤ 20 ppm
Water Solubility	Freely soluble
pH (1% Solution)	7.0 - 9.0

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.