Thing is that salt is so important as a prep, so ignored and so cheap!
http://www.tractorsupply.com/en/store/am...salt-50-lb
Plain old stock salt from the farm supply will work fine for most applications, and can be had anywhere in these type sealed bags. It has unlimited shelf life.
100 pounds of salt for $13 US or about 8 pounds British currency. It is one of the most important and cheapest long term preps one can buy.
It is also a "gray item", considered harmless by one and all. It the farm center asks about its use tell them the truth, it is for meat preservation. If someone sees it that you do not wish to know you are "prepping" just say it is for melting ice on the walkway in winter.