Bellini Sodium Bisulphite (Metabisulphite), 1 kg.

Sodium Bisulphite (Metabisulphite) is a developer preservitive and buffering agent, stop bath and fixer acidifier and clearing bath ingredient to remove certain stains. Being acidic it is also used as a preservative in many two part developers (PMK, Pyrocat-HD, Rollo Pyro, etc.)

Sodium bisulfite is an old name for sodiumhydrogensulfite NaHSO3 and does not exist in solid form.

The molecular formula is: NaHSO3.