Dihydrogen orthophosphate deicing composition

A deicing composition consisting essentially of from about 90 to about 98 weight percent NaCl, from about 2 to about 10 weight percent of a dihydrogen orthophosphate selected from the group consisting of NaH.sub.2 PO.sub.2, KH.sub.2 PO.sub.4, (NH.sub.4)H.sub.2 PO.sub.4, hydroated forms of the dihydrogen orthophosphate and mixtures thereof, and a water soluble magnesium salt in an amount effective to aid the dihydrogen orthophosphate in the reduction of corrosion of ferrous metal by the NaCl in the composition and wherein the water soluble magnesium salt does not exceed about 9 weight percent of the deicing composition.

A deicing composition comprising NaCl in an amount effective deicing and a water soluble dihydrogen orthophosphate in an amount effective for the reduction of corrosion of ferrous metal by an aqueous soltuion of NaCl and a water soluble magnesium salt selected from the group consisting of MgCl.sub.2 .multidot.XH.sub.2 O, MgSO.sub.4 .multidot.YH.sub.2 O and mixtures thereof in amount effective to aid the dihydrogen orthophosphate in the reduction of corrosion of ferrous metal by the aqueous solution of NaCl, wherein the dihydrogen orthophosphate is selected from the group consisting of NaH.sub.2 PO.sub.4, KH.sub.4 PO.sub.4, (NH.sub.4)H.sub.2 PO.sub.4, hydrated forms of the dihydrogen orthophosphate and mixtures thereof and wherein the water soluble magnesium salt comprises not more than about 9 weight percent of the deicing composition and where X =0 to 6 and Y =0 to 7.