Sodium bisulfate is one of the many synonyms for sodium acid sulfate with aformulaNaHSO4. Sodium bisulfate is a combination of sodium, hydrogen, sulfur and oxygen and is classed as a sulfite, or sulfur-based chemical.
It is a dry acid in crystal, granular or powder form but turns yellow in solution. It is used as a pH adjuster, fungicide, herbicide or microbiocide (a product that kills microbes) in a variety of industries, such as household cleaning water treatment, textile dye preparation and film development, but most people are more familiar with its use as a food additive.
Applications of Sodium bisulfate
Probably the largest use for sodium sulfate today is as a filler in powdered home laundry detergents.
The glass industry also provides another significant application for sodium sulfate, consuming around 30 000 tonnes in the US in 1990 (4% of total US consumption). It is used as a “fining agent”, to help remove small air bubbles from molten glass. It also fluxes the glass, and prevents scum formation of the glass melt during refining.
Sodium sulfate is important in the manufacture of textiles, particularly in Japan. It helps in “levelling”, reducing negative charges on fibres so that dyes can penetrate evenly. Unlike the alternative sodium chloride, it does not corrode the stainless steel vessels used in dyeing.
Sodium bisulfate is used to preserve color and inhibit bacterial growth on fruits and vegetables, some seafood and in wine. It was once favored for preserving produce because it kept vitamin C from breaking down, but it not in meat because it destroys vitamin B1.
It is frequently used as a bleaching agent in flour and grains, and as a dough conditioner to enhance the rise and preserve the freshness of bread. Sodium bisulfate occurs naturally in fermented products, so even wines labeled “sulfate free” still contain small amounts.