Are Sodium Bisulfite and Sodium Metabisulfite the Same Thing?

No, sodium bisulfite and sodium metabisulfite are not exactly the same thing, but they are related compounds.

Differences

  • Sodium Bisulfite (NaHSO3) is a chemical compound used as a preservative and reducing agent.
  • Sodium Metabisulfite (Na2S2O5) is frequently used in similar roles (such as preservatives and antioxidants). When dissolved in water, it releases sulfur dioxide and effectively produces sodium bisulfite in solution.

Relationship

When sodium metabisulfite is dissolved in water, it forms sodium bisulfite. Because of this, the two chemicals can sometimes be used interchangeably in certain applications, especially as food preservatives and disinfectants. However, they are not chemically identical in their pure, dry forms.

Summary