Rock Salt as in the rocksalt used to de-ice driveways?

Got a fat bag that just says rock-salt on it, is this right?

is it foodgrade?

is the intended use for it deicing driveways? are you sure it doesnt contain anything else?

If at least its mostly NaCl and the impurities are food safe (such as other mineral salts), then it would be no problem, specialy if you later redissolve and base precipitate the harmalas... But if its some product mixed with other nasty chemicals to aid the melting of ice in driveways (for which they probably dont HAVE to say in the labels because its not supposed to be consumed anyways), then its not good..

Foodsafe pure salt is sooooooooo easy to find, unless you are sure rather not risk it

good call thanks for that, I haven't checked the ingrediants, yet. Which I will do soon.

I just don't see what's so bad about salt with iodide in it. But I am taking the teks word for it.

nothing really bad with iodine in reasonable amounts; SWIM's using table salt (that has traces of iodine as well as other stuff in it). Iodine is present in the sea and its salts (iodide salts like sodium iodide) remain in the salt when sea water is dried to make salt. This is how you make rocks salt. Rock salt is hence supposed to have traces of iodide salts unless someone treats sea salt somehow to remove iodides or if someone synthesises salt from HCl and NaOH to get a salt preparation suitable for (mostly) research purposes.

So if someone is using rock salt to avoid iodine, he's actually not avoiding at all.