Sodium Dithionite / Sodium Hydrosulfite

Sodium Dithionite, also known as Sodium Hydrosulfite, is a powerful reducing agent used in indigo dyeing. It helps convert insoluble indigo pigment into its soluble yellow-green vat form, allowing the dye to bond evenly with fiber and produce clear, strong blues.

It is most often used together with soda ash or another alkaline material to create and maintain an active indigo vat. The right balance between alkali and reducing agent is important: too little reduction may leave the vat inactive, while too much can dull the color or make the vat harder to control.

Sodium dithionite is also used in textile work as a color-removing agent, but it should be handled carefully and only in well-ventilated conditions. It is intended for textile use only.

Best used for: indigo vats, vat reduction, controlled color removal, and textile dye work.

Important notes:
Use only as a reducing agent; it does not produce color by itself.
Add gradually and avoid over-reducing the vat.
Store tightly sealed in a cool, dry place, away from moisture.
Use gloves, avoid breathing dust, and work with good ventilation.

CAS No.: 7775-14-6
EC Number: 231-890-0
Molar Mass: 174.11 g/mol
HS Code: 2831 10 00