Soda crystals (sodium carbonate) are used in the 'non-toxic' etching process to break down and remove acrylic resists and ink grounds when mixed as a strong solution.
Typically this kind of dissolving process takes place through immersion in a concentrated sodium carbonate bath. You can create a stripping bath by mixing up a solution of 1 part soda crystals to 2 to 3 parts warm water. Mild solutions containing soda crystals are also used in the developing photopolymer film and soda crystals are also used to neutralise spent ferric chloride and copper sulphate etching baths.
Soda crystals are a mild irritant so a dust mask and gloves should be worn when handling.
