Calcium chloride
CaCl is hygroscopic so it will harden once exposed to air.. Look for a jug or pail to help but it won't last years lol.
The is one major CaCl producer in America and the Vaporizer producer just signed with them, older stuff will be different material. This main manufacturer also supplies prestone driveway heat, qik joe pellets, qik joe hot flakes, white heat flakes, peladow, and Dow flake. These are really the only ones you would come across in the ny area. The pellets are 90-93% calcium chloride and the flake is 83-87%.
Magnesium chloride is different then a blend as blends are mostly rock salt mixed with other chlorides. Magnesium chloride deicer is only around 50% magnesium chloride (mostly water) in its purest driving form so do not get thrown by any msdsmor spec sheets.
Any questions please shoot me a pm