Acid red 1

Acid Red 1 (CAS 3734-67-6), also known commercially as Red 2G and E128, is a synthetic azo dye used to impart bright red coloration.

Where is Acid red 1 used?

• Textile dyeing: red shades on wool, silk and nylon
• Leather finishing baths: uniform surface color on tanned hides
• Printing inks and packaging: red and pink tones in water-based formulations
• Coatings and adhesives: solution-stable red coloration in aqueous systems
• It functions as an anionic colorant with strong affinity for protein and polyamide substrates.

Good to know: Also marketed as Red 2G and E128. Standard offerings are characterized by dye content specifications rather than pharmacopeial grades.

Commercial specifications

• Purity levels commonly expressed as a percentage of active colorant
• Packaging from small technical quantities to bulk industrial supply