While US personnel in Japan have been issued with supplies of potassium iodide in the event that they need treatment for radiation sickness, it's very much a last-ditch solution.
And while it can prevent against damage from radioactive iodine - just one of many radioactive materials released by a nuclear disaster - there's no effective treatment for radiation sickness, or Acute Radiation Syndrome (ARS).
But this could soon change, as biotech firm Cellerant Therapeutics is working on a new cellular therapy for ARS with funding from the US government's Biomedical Advanced Research and Development Authority (BARDA).
Its CLT-008 is currently being studied as a treatment in patients undergoing cord blood transplants, and in those having radiation treatment for cancer. But, says Cellerant, it could also be used to provide a treatment after exposure to ionizing radiation such as that from a nuclear or radiological weapon, or from a nuclear accident.
CLT-008 is a cell-based therapy that contains human Myeloid Progenitor Cells, derived from adult stem cells, that have the ability to mature into white blood cells. It's the destruction of these by radiation that leaves the victim open to infection and often causes death.
In preclinical models, it's already been shown to be highly effective in providing protection from lethal radiation. It appears to provide an effective treatment for ARS in an emergency, and can be given up to five days after exposure to radiation.
"We believe Cellerant is at the forefront of the development of a solution for ARS and we share BARDA’s commitment to developing CLT-008 as an effective countermeasure to support our biodefense interests," says president and CEO Ram Mandalam.
While some Californian suppliers of potassium iodide say they've been deluged with customers wanting to stock up in the light of Japan's nuclear disaster, it's not something you'd want to take unless you had to.
It works by preventing damage to the thyroid, which can reduce the risk of developing cancer later on. But it can be extremely dangerous to people with thyroid problems, as well as anybody with an allergy to iodine or shellfish - which many people have unknowingly.