Calcium nitrate tetrahydrate

Calcium nitrate tetrahydrate, commonly written as Ca(NO3)2·4H2O, is an inorganic calcium salt supplied in hydrated crystalline form. It carries no E-code designation and is distinct from anhydrous calcium nitrate in its water content and handling characteristics. It is also referred to as Norwegian saltpeter in fertilizer trade contexts.

In concrete and construction chemistry, it accelerates cement hydration and acts as a set accelerator and antifreeze additive at low temperatures. In water treatment, it supplies soluble calcium to support coagulation and correct calcium hardness imbalances. In agriculture, it delivers both nitrate nitrogen and calcium directly to plant root zones through fertigation systems.

The product is available in technical and fertilizer grades, typically supplied as prilled or granular solid in 25 kg bags or bulk tote formats. It falls under REACH registration requirements for industrial supply within the EU. No Ph.Eur. or FCC monograph applies to standard industrial grades.