... .White odorless powder 4.Over 50 years factory Sodium Tripolyphosphate (STPP) Food GradeSpecificationFood grade Main content, %,≥96.0 P2O5 %≥57.0 Water insoluble ... , dyeing, petrochemical industry, tanning industry, metallurgical industry and building material industry, and used as a water softening agent in solution for printing, dyeing, and boiler, as diffusant ...