I've been doing some reading on this subject recently, since it's about time for me to swap out the distilled water/Water Wetr mix for antifreeze for the winter.
Ethylene glycol, the green default antifreeze since WW2, is indeed caustic to metals and of course, poisonous to critters to boot.
I find it curious that some folks are selling a propylene glycol based antifreeze these days (such as Amsoil). Being in the fire protection biz all my adult life, I'm very familiar with propylene glycol, since it's what we typically use in antifreeze based fire sprinkler systems.
Use of this particular product comes with its' own issues, namely, the stuff is VERY expensive these days (thanks, EPA). It's also, ironically, VERY flammable unless it is sufficiently diluted with water - which is why antifreeze "loops" aren't allowed to be installed for fire protection anymore.
Not good when the fire protection becomes the fire
accelerant, you know.
The Evans waterless coolant is attractive, until you figure cost into it. Ouch.
It's also ironic, at least to me, that another suggested replacement for ethylene glycol these days is glycerine based - the product ethylene glycol was first developed to replace back in the late 1800's because it was so expensive to produce.
They were both first created to be used in the production of high explosives (dynamite).
What to use, indeed?