Iodine and minimising corrosion

Corrosion is a major problem with oxidising sanitisers which can cause expensive damage to plant equipment after a period of time.

Both iodine and chlorine cause various degrees of corrosion. However, the corrosion effect of chlorine is dramatically more than iodine as delivered in the Isan System for the following reasons:

• The fundamental measure of corrosion is the oxidation potential of the atom. Chlorine has an oxidation potential of 4.9 whereas iodine has an oxidation potential of 4.2. Since this is a logarithmic reference, the reactivity of chlorine is twice that of iodine;
• The atomic weight of chlorine is 35.5 as against iodine which is 127. Therefore, for an equivalent weight of product there will be 3.6 times (127/35.5) more chlorine atoms than iodine atoms.
  
• When you combine these two facts you end up with a theoretical increased corrosion effect of chlorine over iodine of more than seven times;
  
• the dosages of iodine as dispensed by the Isan System, necessary to be as effective or more effective than chlorine are between five to ten time less than chlorine. So not only is the iodine significantly less corrosive but the dosages present are significantly less;
  
• Another significant corrosion generator in chlorine based systems is the presence of chlorine by-products nearly all of which are highly corrosive in their own right. These by-products are not removed from the wash water and build up to very high levels compounding the corrosion effect. In dramatic contrast the Isan System constantly removes the iodine by-products from the wash water thereby removing any corrosion effect that they might have had;
  
• Finally, the differences in gaseous formation is significant. At room temperature chlorine is a gas but iodine is a solid. In addition,, particularly due to the higher dosages and effect of pH and temperature, there will always be substantially more chlorine gas produced than iodine gas. This chlorine gas, also highly corrosive, permeates throughout operators plants affecting all equipment.

For all of these reasons the iodine as used in the Isan system is only slightly corrosive in comparison to chlorine sanitizers. The Isan System once installed will result in significantly longer equipment life leading to substantial capital equipment cost savings.