... salt, Metaphosphoric acid. Specs: Tech Grade: Total phosphate, as P2O5---------- 68.0% min Inactive phosphate, as P2O5 ------7.5% max ... Water insoluble ---------------------0.05% max Food Grade: Total phosphate, as P2O5---------- 68.0% min. Inactive phosphate, as P2O5 ------7.5% max. ... , detergent and soil analytical chemical reagent; 2. Food grade: Mainly used as additive agent, pH adjusting agent, ...