Dye intermediates

These chemicals are made mainly in India and China, where dye and pigment production is concentrated, and they move between specialist producers and dye makers. Many are also used in pharmaceutical, agrochemical and rubber chemical synthesis.

Specify the purity by HPLC or titration, moisture, insolubles, iron and the content of isomers or related compounds, which affect the shade and strength of the final dye. Many intermediates are toxic, sensitising or hazardous to the environment, and effluent rules affect where and how they are produced, so supply can tighten when plants close for environmental reasons. Most intermediates fall under HS chapter 29, in the amine, sulfonic acid or heterocycle headings.