Toxicity
Non-toxic to skin but if you get it in the eyes or mouth it would be irritating.
Stability
Stable under regular conditions. (room temp.)
Odor
The compound is odorless. This makes it perfect for an additive for food.
pH
5.5 - 7.7
Reaction Tendencies
Sodium Hexametaphosphate basically only reacts when presented with a salt. In this occasion it will form precipitates and in some cases entire precipitation can occur. This compound helps stop corrosion from calcium, iron salts and manganese and many more.