TOKYO (CNN) - Radioactive cesium has been found in baby formula in Japan following the nuclear crisis at the Fukushima Daiichi plant, the manufacturer of the product has said.
Meiji Co., the maker of the formula, said Tuesday it had found traces of cesium 134 and cesium 137 in samples of its Step Milk powder with the expiration date of October 2012, but the levels would not be harmful to babies' health.
The formula contained as much as 31 becquerels of cesium per kilogram, below the allowable limit of 200 becquerels per kilogram set by the government, Meiji said.
A becquerel is a measurement of radioactive intensity.
A spokesman for Meiji said the company would nonetheless offer free replacements of 400,000 cans of the product "to relieve the anxieties of our customers."
Ingredients of the baby powder may have come into contact with airborne radioactive cesium when they were being dried at a factory in Kasukabe, about 40 kilometers (25 miles) north of Tokyo, between March 14 and 20, the company said.
The devastating earthquake and tsunami that struck the northeast coast of Japan on March 11 damaged nuclear reactors at the Fukushima Daiichi plant, resulting in radiation leaks.
Meiji accounts for about 40 percent of baby formula sales in Japan. It also exports the Step Milk formula to Vietnam under a different name, but it says it examines the product before shipping.