Tap water, salt makes cooked food toxic

Researchers have found several molecules that are almost completely new to scientists, created by cooking with chloraminated tap water and iodised table salt. They said that limiting cooking time and temperature, and cooking with table salt fortified with iodate instead of iodide, could be safest.

Our tap water is disinfected before we drink it or use it in cooking. This is done in several ways, including by adding chlorine or molecules called chloramines that are made using ammonia.

These two processes -chlorination and chloramination -have an effect on the chemical make-up of the water. Chlorine or chloramines in tap water can react with the iodised table salt added to food, creating a kind of acid called hypoiodous acid.

The acid can then react with the food and other organic matter in the tap water to create cooking iodinated disinfection byproducts (IDBPs) -molecules that are new to researchers.