While WA is far from being a “rustbelt” - thought I’d comment that our state switched from non-salt de-icer to straight salt some decade back for the exact reason
@Wompom touched on - the salt goes down drains & ends up in the ocean & we’re trying to protect salmon/the ocean in general.
So since my 80 is my go-to vehicle over the Tundra in frozen conditions, and my dedicated rig for going up to Mt Baker ski area, I may start going to a preventative coating since we all know once rust gets a start on a Yota, it is like a kid who discovers Pop Rocks
Alot of people never heard we as a state switched until this last Winter we had a shortage of road salt that made the news, and people thought we were still using calcium chlorate (or whatever it was called, I forget TBH).
But people here should keep it in mind we’re a salt state now. —Take it as you like.—