Phosphates and phosphorus salts

Fertilizer phosphates such as monoammonium and diammonium phosphate are the largest volumes. Industrial and food grades are used as leavening acids in baking powder, emulsifying salts in processed cheese, water retention agents in meat and seafood, mineral fortificants, detergent builders, scale and corrosion inhibitors, dispersants for ceramics and drilling muds, and metal treatment chemicals. Dicalcium and monocalcium phosphate are standard phosphorus sources in animal feed.

The P2O5 content or phosphorus percentage, pH of a solution, water insolubles, fluoride, arsenic, lead and cadmium are the key specifications. Food grades should meet the Food Chemicals Codex or national food additive specifications, and feed grades the fluoride limits that apply in the destination market. Fertilizer phosphates fall under HS chapter 31, while technical, food and feed phosphates fall under HS heading 2835.