Description

Acid Red 4 is a synthetic, water-soluble azo dye belonging to the acid dye class, identified by CAS NO 5858-39-9. It is valued for its bright, vivid red color and good affinity for protein-based fibers like wool, silk, and nylon. This dye is essential for manufacturers in the textile, leather, and paper industries seeking reliable and consistent coloration. Its properties also make it suitable for specialized applications in biological staining and as a colorant for various substrates.

Application

• Textile Dyeing: Primary application for dyeing wool, silk, nylon, and other polyamide fibers.
• Leather Coloring: Used for imparting red shades to leather goods and accessories.
• Paper Staining: Employed in the production of colored papers, tissues, and specialty packaging.
• Biological Staining: Serves as a histological stain in laboratory settings for microscopic analysis.
• Ink Formulation: A component in the manufacture of inks for various printing applications.
• Food Contact Material Coloring: Potential use for coloring materials intended for food packaging, subject to regulatory compliance.

Basic Information

Product Name	Acid Red 4
CAS No.	5858-39-9
Molecular Formula	C18H14N2Na2O7S2
Molecular Weight	480.42 g/mol
Synonyms	Acid Red 4; C.I. 14710; Food Red 5; Amaranth; Azorubin S; Acid Amaranth; Wool Red D; C.I. Acid Red 4; E123 (when used as a food additive)
EINECS	227-512-5

Quality Control

Our Acid Red 4 is manufactured under a strict quality management system to ensure batch-to-batch consistency and performance. Each lot is tested against rigorous specifications for color strength, purity, solubility, and heavy metal content. A comprehensive Certificate of Analysis (COA) detailing all test results is provided with every shipment. We ensure compliance with relevant industry standards for its intended applications.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at room temperature (15-25°C). Keep away from incompatible materials. Due to its light-sensitive nature, prolonged exposure to direct light should be avoided to maintain color stability.

Specification

Item	Specification
Appearance	Dark Red to Brownish-Red Powder
Identification (IR)	Conforms to Standard
Assay (HPLC)	≥ 85%
Color Strength	100 ± 3%
Moisture Content	≤ 5.0%
Water Solubility	Conforms
Ash Content	≤ 1.0%
Heavy Metals (as Pb)	≤ 20 ppm

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