It’s a chelation liquid
Not acid not basic
It modified water’s ability to dissolve otherwise non water soluble salts and oxides
For instance aluminum oxide and iron oxide become soluble like table salt but slower in water with a chelation molecule
Chelation is also used in medicine to pull metals from your body
It’s not a straight forward chemical it’s a family of large organics that do this trick and they are manufactured in large volumes for industrial processes
But evaporust is suppose to be environmentally friendly and safe for your skin and disposal is only critical to the metal oxide you used it on, so if you clean up a lot of lead for instance then that would be bad to dump
But iron and aluminum would be safe to dump as iron and aluminum make up a large faction of normal soil.
-s