The fires and explosions at Fukushima Daiichi nuclear plant have prompted a massive increase in the sale of anti-radiation tablets in the US and Canada - despite health officials and a prominent UK scientist dismissing it as unnecessary.
Companies in North America have reported selling out of potassium iodide supplements, which can prevent the body absorbing radioactive iodine, while in the UK one chemical manufacturer has reported a "surge" in inquiries about the chemical.
Medical authorities in California have warned against taking the drug, which can cause side effects, according to The Guardian.
Anbex Inc., the main U.S. manufacturer of potassium iodide tablets, also is nearly sold out of its supply and said it is working to produce more of the medicine in the coming weeks.
Potassium iodide is different from iodine, an element most often used as a disinfectant, California Department of Public Health spokesman Mike Sicilia said.
Hundreds of calls have been pouring into a hotline set up Monday to field questions about radiation after the disaster in Japan, Sicilia said, The Desert Sun reports.