Well, water and salt are toxic as well, in sufficient quantities.
Better stop eating those as well. 
I doubt they're equivalent.
Yes it's important to stay well hydrated but one can over do it.
I try to stay away from salt...so much so that now everything tastes too salty to me now.
Both are examples are done with the knowledge of those substances and the option to make the right choices.
But it seems not everybody is aware of the dangers of the seemingly innocuous.
When it comes to things that are carcinogenic...sometimes the government has to step in.
I've not heard of water and/or salt being carcinogenic.