Phosphoric acid

Phosphoric acid (CAS 7664-38-2), also known as orthophosphoric acid and designated E338 in food applications, is a mineral acid used across industrial, food, and pharmaceutical sectors. It functions primarily as a pH regulator, acidulant, chelating agent, and surface treatment chemical depending on the application. In food and beverage production, it acidifies carbonated soft drinks and acts as a flavor modifier.

The FEMA 2902 recognition supports its use in flavoring systems. Metal surface treatment relies on phosphoric acid for rust conversion and phosphate coating prior to painting or galvanizing. Water treatment facilities use it to dose phosphate for corrosion inhibition in distribution pipelines. Pharmaceutical and industrial cleaning formulations incorporate it for pH adjustment and as a sequestrant.

These formulations stabilize active ingredients against metal ion interference. Phosphoric acid is supplied as an aqueous solution, with 75%, 80%, and 85% concentrations being the most commercially standard. Food-grade material is available to FCC and E338 specifications, while pharmaceutical-grade supply meets USP and Ph. Eur. requirements for various manufacturing needs.

Technical-grade solutions are used in industrial processing where food or pharma compliance is not required. This versatile chemical remains a cornerstone for acidity control and surface preparation globally.