These guidelines are an update of the 1999 World Health Organization
(WHO) guidance on the use of iodine thyroid blocking (ITB) with a
special focus on public health considerations of ITB
implementation.These guidelines provide a recommendation on iodine
thyroid blocking (ITB), via oral administration of stable iodine, as an
urgent protective action in responding to a nuclear accident. This
recommendation aims to support emergency planners, policy makers, public
health specialists, clinicians and other relevant stakeholders, in order
to strengthen public health preparedness for radiation emergencies in
WHO Member States as required by the International Health Regulations
(IHR) and in line with the international safety standards (GSR Part 7).
The scope of the guidelines is confined to public health aspects of
planning and implementation of ITB before and during a radiation
emergency, such as dosage and timing of ITB administration, adverse
effects of stable iodine, its packaging, storage, and distribution.