Monosodium Phosphate Supplier South Africa

What Is Monosodium Phosphate?

Monosodium phosphate (NaH₂PO₄, sodium dihydrogen phosphate, MSP) is the monobasic sodium salt of phosphoric acid — where only one of the three acidic protons of H₃PO₄ is replaced by sodium. It is a mildly acidic compound, with a 1% solution pH of ~4.4. MSP is the acidic member of the sodium phosphate family and is used alongside DSP (Na₂HPO₄, pH ~9.5) and TSP (Na₃PO₄, pH ~12) to prepare phosphate buffer systems across the acidic-to-alkaline pH range. Together with DSP, monosodium phosphate forms phosphate buffers at pH 5.8–8.0.

Boiler Water and Water Treatment Applications

In boiler water treatment, MSP is used for pH depression where boiler water alkalinity is excessive and needs to be reduced. In high-alkalinity, high-silica boiler systems, lowering pH with MSP controls silica deposition risk. MSP is also used in pH adjustment of process water streams where mildly acidic conditions are required. As a phosphate compound, MSP provides the phosphate nutrition required by bacteria in biological wastewater treatment systems (biological nutrient addition) when phosphate is the nutrient limiting biological treatment efficiency.

Food and Pharmaceutical Applications

In food processing, monosodium phosphate (E339i) is an approved food additive used as an acidulant, buffering agent, pH control agent, and sequestrant. It is used in carbonated beverages, dairy products, processed meats, and baked goods. In pharmaceutical manufacturing, MSP is a standard buffer salt used in oral, injectable, and topical pharmaceutical formulations to achieve and maintain target pH. In laboratory and analytical chemistry, sodium dihydrogen phosphate is a primary standard for phosphate buffer preparation (e.g., PBS — phosphate buffered saline — for cell culture). Terracore Chemicals supplies MSP in technical and food grades in 25 kg bags.