What's the scoop with magnesium chloride? Corrosive?

[Spartan]

They mix the mag with water but it's not just liquid salt. It's totally corrosive and is banned in places for environmental reasons. It kills rainbow trout and other aquatic life as runoff. I would prefer a chance to go fishing over deiced roads myself. It doesn't snow much at my place tho. I do have studs if I need them tho.
IMHO the trout win out. I lived in lake Tahoe where salt are banned and rock works fine.