Potassium Iodide Dosage, Shelf Life and Sources
Updated July 16, 2000
What is the daily dosage required?
Current FDA guidelines call for the daily administration of 130
mg. of potassium iodide (KI)) for up to 14 days for adults and
children over 60 pounds. Smaller children should take one half
tablet for 14 days.
Recent findings and the experience at Chernobyl (where 18 million
children were given KI) suggest KI is even more effective than
previously realized, and that thyroid blocking can take place
at smaller doses. As a result, FDA is considering reducing the
amount of the dosage, and is studying dose levels as small as
16 mg. for infants and 32 mgs. for small children for shorter
periods. Currently, however, package instructions should be followed
in the event of a large release of radioactive iodine from a power
plant accident or a nuclear weapon.
How long is the shelf life of potassium iodide?
Potassium Iodide is inherently stable. If kept dry in an unopened
container at room temperature, it can be expected to last indefinitely.
Potassium Iodide works by "saturating" the thyroid with stable
iodide so it will not absorb radioactive iodine that might be
released in an accident. Under current dosing guidelines, a fully
saturated thyroid would be protected for up to one month, which
is long enough for radioactive iodine (which has a half life of
8 days) to disappear from the environment.
What is the US Government position on providing KI to workers
and the public in the event of another nuclear emergency?
The U S Nuclear Regulatory Commission (NRC) does not dispute the
safety or effectiveness of KI. In fact, they require nuclear power
plants to stockpile it to protect plant workers, and FEMA (Federal
Emergency Management Agency) plans call for KI to protect those
individuals who would be unable to be evacuated in a nuclear accident
especially those under the care of the government (such as prisoners
or patients in government hospitals).
But the NRC is resisting the calls for a national stockpile of
KI, claiming it is "unnecessary." As a result, the US remains
the only major nuclear power that does not have a supply to protect
its citizens. Recently, to counter the widespread criticism of
this policy, the government announced it had established a "national
stockpile" of KI. This news was welcomed by many in the scientific
community. However, at a recent meeting, the NRC admitted that
its operational "national stockpile" consisted of only 2500 tablets,
not even enough for 200 people.
As a reaction to criticism by US medical groups and the World
Health Organization, the NRC has announced it would make KI available
(free of charge) to state or local governments desiring it. Again,
this news was greeted with enthusiasm. However, following this
announcement, the NRC "clarified" its position, and now says it
will provide KI only to those people living in communities within
the 10 mile "EPZ" (Emergency Planning Zone) surrounding nuclear
plants. Given that most casualties in a nuclear accident would
take place more than 50 miles from the plant (following Chernobyl,
thousands of cases of childhood thyroid cancer developed hundreds
of miles away), the current NRC position is probably of questionable
SOURCES FOR POTASSIUM IODIDE - KI
Anbex, Inc - 130 mg. per tablet, 14 tablets per package; 1 - 10 Packages
$10.00/Package; Shipping and Handling $4.00 Per Order
COSMOS Online* Trade Center - 16 suppliers in Mexico
KI4U.com - see site for various pricing
Lab Depot - Potassium Iodide, Granular, Reagent, ACS $84.60
Outdoor Depot - One bottle contains a 2-week supply for one person. $49.95
SOURCES FOR POTASSIUM IODATE - KIO3
B&A Products - bottle of 100 tablets of 150mg is $18.00, Two bottles is 33.00,
Three bottles is 48.00, Four bottles is 64.00
KI4U.com - see site for various pricing
Medical Corps - 100 150mg tablets per bottle: $16.95 a bottle, $29.95 for 2
bottles, postage paid
Outdoor Depot $19.95 100 fresh tablets of Potassium Iodate 150mg tablets
Potassium Iodate or Potassium Iodine - Which Do I Use?
I contacted at least 12 different companies and agencies regarding
the difference in using Potassium Iodide and Potassium Iodate.
The most unbiased answer came from Marcia Carpenter, Radiological Emergency Response Team U.S. Environmental Protection Agency Marcia writes:
"In response to your question about potassium iodate versus iodide,
here are the basics:
Potassium Iodate (KIO3) and Potassium Iodide (KI) are not the same.
KIO3 - molecular weight 214.00 is 18.27 % K, 22.43 % O and 59.30 %
I, so you would have to
administer 168.63 milligrams of KIO3 to deliver 100 milligrams of iodine.
KI - molecular weight 166.01 is 23.55 % K and 76.45 % I, so you
would have to administer 130.81
milligrams of KI to deliver 100 milligrams of iodine.
Both compounds are soluble in water, but KI is very soluble. KI
is much less stable than KIO3. When
KI breaks down, it becomes yellow due to release of iodine and
it may produce small amounts of
iodate. When iodate breaks down, it also produces a yellow color
from iodine. Both compounds should
be protected from light and moisture to improve stability.
As to which is preferred for use in the event of nuclear accidents,
I can refer you to the following quote
and its associated reference. The quote is from a World Health
Organization (WHO) and International
Atomic Energy Agency (IAEA) working document entitled "Guidelines
for Stable Iodine Prophylaxis
Following Nuclear Accidents," dated 10/19/98.
And I quote...
- "Stable iodine can be used as either potassium iodide or potassium
iodate. Potassium iodide (KI) is the preferred alternative, since
potassium iodate (KIO3) has the disadvantage of being a stronger intestinal irritant."
- Since this document is still in draft, you might want to go to
the original work they cite. It is:
Rubery ED. Practical aspects of prophylactic stable iodine usage.
In: Iodine Prophylaxis Following Nuclear Accidents -- Proceedings
of a Joint WHO/CEC Workshop, July 1988. Pergamon Press, Oxford,
1990. pp 141-150.
The U.S. Food and Drug Administration is currently doing a reassessment
of various recommendations on this issue, but their work is not
- B&A Products website states:
"Potassium Iodate is a superior form of Potassium Iodide (KI)
because of extended shelf life and lack of bitter taste. The extra
molecule of oxygen in Potassium Iodate (KIO3), can guarantee the Iodate's continued freshness without adding
- Additional research, information and sources
- KI4U - Excellent in-depth FAQ
Conclusion - either Potassium Iodate (KIO3) or Potassium Iodide (KI) is fine.