Experts warned on Tuesday that consumers should not swallow disinfectants and gargles containing iodine as an alternative to stable iodine that eases health damage caused by radiation exposure.

The warning was issued amid a sharp increase in demand for the disinfectants and gargles after the detection in Tokyo of small amounts of radioactive substances, including iodine and cesium, apparently due to the trouble at the Fukushima No. 1 nuclear power plant in northeast Japan following last Friday’s earthquake and tsunami.

The disinfectants and gargles contain various substances that become harmful to health if taken orally, the National Institute of Radiological Sciences said.

Demand for products containing iodine has soared due in part to false information spread online that they can be used as alternatives to stable iodine.

Many retailers are also short of dry cells, bottled water and other products amid soaring demand following the earthquake.