Acid green 5

Acid Green 5 (CAS 5141-20-8) is a synthetic triarylmethane dye also identified by the designations CI 42095, my/68, c.i.670, NSC 9619, and MIDORI205. It carries no assigned E-code, confirming its restriction to industrial rather than food-contact applications. It is classified under HS code 32041200 as a synthetic organic colorant.

In textile dyeing, Acid Green 5 bonds ionically to protein fibres such as wool and silk under acidic bath conditions, producing deep green shades with good levelling characteristics. It is also applied in leather finishing to achieve consistent surface coloration, and in paper manufacturing where it is retained by cellulose fibres during the wet-end process.

Acid Green 5 is supplied as a deep purple crystalline powder and is subject to REACH registration requirements for EU market supply. Procurement teams should confirm supplier SDS documentation and batch purity specifications prior to ordering. Standard packaging formats vary by supplier volume tier.