... ,Manufacturer of Sodium Tripolyphosphate (STPP) 2,Free sample 3,High quality and ... chelating ability to some metal ions such as Ca 2+, Mg 2+, can soften hard water, change suspension into ... solution, slightly alkaline, without causticity. 2, Usage: Used as main auxiliary of synthetic wash, ... 0.015 pH of 1% water solution 9.2-10.0 2. Food grade Main content, %: 94.0 P2O5 ...