Sodium sulfite is a chemical compound with the formula Na2SO3. It appears as a white, crystalline powder and is commonly used as a preservative and antioxidant in food and beverages. In addition to its culinary applications, sodium sulfite is also utilized in various industrial processes, such as water treatment and paper manufacturing. This compound is soluble in water and can release sulfur dioxide when it reacts with acids. Sodium sulfite is important in photography as a developer and fixer, helping to stabilize images. However, it can cause allergic reactions in some individuals, particularly those with asthma.