Iodised table salt contain sodium chloride, potassium iodide (or iodate) and anticaking substances.
Iodised salt
Iodised salt is recommended to avoid idiocy.See this link: http://en.wikipedia.org/wiki/Iodised_salt.
The healthier salt is iodised; but the sea salt can be also iodised.
Iodised salt (sodium chloride) contain iodine (as potassium/sodium iodide or potassium/sodium iodate). The concentration of iodine is 20 +/- 5 mg/kg. Iodised salt is recommended to avoid idiocy.
NO !!
waitrose or ocado
Salt, or table salt (NaCl) is a substance because NaCl is a compound. However, salt dissolved in water is a mixture because the sodium and chlorine ions dissociate.
Pure salt is a compound made from Sodium (Na) and Chlorine (Cl). Its formula is NaCl and it is a pure substance not a mixture. However, most salt you purchase from a shop as' Table Salt' is iodised (for health reasons) and contains anti caking agents (to make it run). That is, it has had iodine other substances added to it. This makes Table Salt a mixture.
Thankfully it is now very easy to get non-iodised salt at local grocery chains. Brands like Kroger, Harveys, and Publix all have store brand non-iodised salt. Lawreys and Morton also sell a non-iodised salt on their website.
See the following link: http://www.sspindia.com/salt-processing-plant.html#iodised-salt-processing-plant.
Iodised salt contains a very small amount of iodine added to prevent iodine deficiency. When heated during cooking, the iodine content in iodised salt does not vaporize or sublimate significantly to create a health concern. Hence, the amount of iodine present in the food after cooking from iodised salt is negligible and safe.