Gobar Times
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Iodised salt


To take, or not to take

Pure, free-flowing, iodised salt’… the most common tag-line for advertising salts. But, is it as catchy as it sounds?


Iodine deficiency affects 740 million people a year (WHO). According to government surveys by the Indian Council of Medical Research an estimated 64 million Indians suffer from Iodine Deficiency Disorder (IDD). It is linked with goitre, cretinism, defects in speech and hearing, and brain damage. In developing foetus, baby and young child, iodine deficiency may affect growth, diminish intelligence and cause retardation. And iodised salt helps to balance this deficiency, saving us from fatal diseases.

Iodised salt may cause Hyperthyroidism (excess iodine in the body). It may raise the body’s requirement of vitamins and cause a ‘relative vitamin deficiency’. It can adversely affect blood flow and heartbeat, and cause depression in heart muscle strength and increase arterial pressure. Appetite and food intake may rise sharply, resulting in diarrhea. Muscle tremour, extreme nervousness, fatigue and psychoneurotic tendencies like anxiety complexes, paranoia and worry are other major effects of excess iodine.


Recently, the Supreme Court admitted petitions for detailed hearing against the Centre’s decision to make iodisation of salt compulsory. The petitioners claimed that excessive use of iodised salt might lead to various health problems. But, as we all know iodine is essential for our health, and iodised salt provides this micronutrient.

It is a hot debate. Here are certain aspects that may make us think twice before deciding. Iodised salt is not a chemical compound as salt iodisation is not a chemical process. It is only a physical process of mixing the iodine compound with common salt.

The iodine compound required for iodising one tonne of salt is just 50 grams. This iodised salt is a heterogeneous mixture. Its homogeneity depends mainly on the uniformity in the size of the particles of salt and the iodine compound. But, common salt is never of same particle size. Thus, the iodine content of iodised salt cannot be fixed.

The only allowance is that different specifications have been laid down for manufacturing and consumer ends, 30 parts per million (ppm) and 15ppm respectively. On the other hand, the prevalent medical belief is that the body rejects excess iodine. According to the World Health Organisation (WHO), “on a population basis, the benefits of correcting iodine deficiency through universal salt iodisation vastly outweigh the risk of iodine-induced hyperthyroidism.”

World scenario

Several countries, such as USA, England, Italy, Germany, Japan, Switzerland and Australia, abandoned compulsory iodisation in the 1940s after deaths were recorded in the US and England from hyperthyroidism. Many African countries subjected to high doses of iodisation suffered iodine-induced hyperthyroidism (IIH) outbreaks as late as in the 1990s. In 1995, the incidence of IIH in Zimbabwe went up by 27 per cent! But, there is a lack of comprehensive data on the incidence of IIH in India. Improvement in diet is the only solution to the iodisation debate.

But, in a country like India where getting food seems like a Herculean task, balanced diet does not even come into play. What is required is not to fight and win this debate, but to do intensive scientific research specific to India and its conditions.


Salt iodisation process

There are three processes:

  • Dry Mixing process: The mixing of salt with potassium iodate in screw conveyors.
  • Spray mixing process: The spraying of a solution of potassium iodate in water on salt falling from belt conveyors and passing it through screw conveyors for further mixing.
  • Submersion process: Salt is treated with a solution of potassium iodate in a tank and the crystals obtained are collected and dried.




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To take, or not to take