Povidone-iodine in people with thyroid problems. Povidone-iodine is a chemical complex of povidone, hydrogen iodide, and elemental iodine. It contains from 9% to 12% available iodine. It works by releasing iodine which results in the death of a range of microorganisms. Povidone-iodine came into commercial use in 1955. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. Povidone-iodine is available over the counter. The wholesale cost in the developing world is about 3.30 to 11.40 per liter of 10% solution. This amount in the United Kingdom cost the
Iodine 1% of a sample of gaseous iodine at atmospheric pressure is dissociated into iodine atoms at 575 °C. Temperatures greater than 750 °C are required for fluorine, chlorine, and bromine to dissociate to a similar extent. Most bonds to iodine are weaker than the analogous bonds to the lighter halogens. Gaseous iodine is composed of I molecules with an I–I bond length of 266.6 pm. The I–I bond is one of the longest single bonds known. It is even longer (271.5 pm) in solid orthorhombic crystalline iodine, which has the same crystal structure as chlorine and bromine. (The record is