Denim Finishing
Permanganate does not stop when the spraying stops. Under-dose the bisulfite and the bleach keeps working in the stack.
— g
Including safety excess and corrected for purity
Stoichiometry gives the floor, never the working dose — spray distribution is uneven and unreacted permanganate sits in the heaviest areas, which is why the excess exists. Bisulfite releases sulfur dioxide in acid conditions and permanganate is a strong oxidiser; both demand ventilation, PPE and a residual-permanganate check on the garment before the load moves on.
PP Spray Neutralisation Bisulfite Dosing Calculator — free, with the formula and a worked example, at Textile School.