Testing Iodine Content of Salt:
Kit and Home Based Methods
Ms Cadi Parveen Banu
Institute of Nutrition and Food Science,
University of Dhaka
Salt Iodization Program in BangladeshSalt Iodization Program in Bangladesh
• During the period 1962-1964, the first National
Nutrition Survey was carried out in Bangladesh ( the
then East Pakistan) identified prevalence of hyper
endemic goiter .
• The second nutrition survey was organized in rural
areas of Bangladesh in 1975-76.Both the survey
reported that average prevalence of goiter was
found to be 28.9% and 13.8% in 1962-64 and 1975-
• The first National Goiter Prevalence study of
Bangladesh was conducted in 1981 by the
Institute of Public Health Nutrition (IPHN).
• During survey, only goiter was assessed; no data
on cretinism or other consequences were
• The survey revealed, a wide prevalence of goiter
to varying degree all over the country with an
average national prevalence rate of 10.51% and
some areas of high endemicity of goiter (e.g.
Law for Universal Salt Iodization
• In 1989 Government of Bangladesh passed a
law making it mandatory the universal
iodization of all edible salt.
IDD Situation of Bangladesh According
to National Survey,1993
• A by-law was passed in 1994 only then
substantial improvement was made in the
infrastructure of universal salt iodization
Universal Salt iodization
• For the assessment of iodine content of salt
USI survey was conducted in 1996 and 1999
• During the period of 1996-99, the percentage
of adequately iodized salt at HH level (≥15
ppm) was maintained at 54 to 55%.
• At the factory level 4.8% salt had adequate
iodine (45-50 ppm).
IDD Situation of Bangladesh According to
• The overall prevalence of iodine deficiency was
33.8% and 38.6% among the children and women
• High Prevalence of IDD among the children and
women was observed in some selective areas.
Methods for Testing Iodine in Salt
• Iodine is added in the form of KIO3 to
iodize the salt in Bangladesh.
• Iodine can be set free from KIO3 in
iodized salt by addition of acid.
• The liberated iodine forms violet color
complex with starch.
Home based method: testing
• Take one tea spoon of household salt
• Mix with 5 grains of cooked rice
• Then add a few drops of lemon juice
• Salt will turn purple if it contains iodine
• There will be no color change if it does
Testing Kit: Developed by IFST, BCSIR
• A leveled spoonful of salt is taken in a marked
transparent plastic container
• A small amount of working solution (bottle 2)
is added to the salt in the container
• The container is swirled till the salt dissolves
• Then more working solution will be added to
bring the volume up to the mark of the
container and mix thoroughly.
• About 10-15 ml of salt solution will be taken in
• A piece of paper strip will be dipped in the salt
• Allow to develop the violet color (7-10 sec)
• Comparing the developed color with the
supplied colored chart.
• Read out the amount of iodine in salt.