Sodium Sulfite

Products

Sodium sulfite is used as an excipient in pharmaceuticals. It is also used for food and cosmetics.

Structure and properties

Pharmacopoeially monographed sodium sulfite heptahydrate (Na₂SO₃ – 7 H₂O, M_r = 252.2 g/mol) exists as colorless crystals and is readily soluble in water. It can be prepared with, for example, sulfur dioxide and sodium hydroxide.

• SO₂ (sulfur dioxide) + 2 NaOH (sodium hydroxide) Na₂SO₃ (sodium sulfite) + H₂O (water)

Sodium sulfite is the sodium salt of sulfurous acid.

Effects

Sodium sulfite has preservative, antimicrobial and antioxidant properties. It is effective against microorganisms such as fungi.

Fields of application

As a preservative and antioxidant.

Contraindications

• Hypersensitivity

Adverse effects

Possible adverse effects include allergic reactions.