Facilitators of Change - USDA

These detergents work best in water that has little calcium and magnesium, as these elements bind to the detergent and make an insoluble scum. So tetrasodium EDTA (ethylene diamine tetraacetate) is used to sequester the calcium and magnesium from the detergent, while keeping them soluble so they rinse away without scum. ................
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