... 4.Over 50 years factory Sodium Tripolyphosphate (STPP) Food GradeSpecificationFood grade Main content, %,≥96.0 P2O5 %≥57.0 Water insoluble ... Ba, Mg, Cu and Fe 3. Application: 1). Technical grade: Used in such industries as oil field, paper-making, textile ... agglomerant, detergent and soil analytical chemical reagent; 2). Food grade: Mainly used as additive agent, pH adjusting agent, fermenting ...