U.S. safety officials have recalled about 4.2 million Chinese-made Aqua Dots bead toys that contain a chemical that has caused some children to vomit and become comatose after swallowing them.

Scientists have found the popular toy's coating contains a chemical that, once metabolized, converts into the toxic "date rape" drug GHB, or gamma-hydroxy butyrate, U.S. Consumer Product Safety Commission spokesman Scott Wolfson told CNN.

"GHB is this drug that in low doses actually causes euphoria," said Dr. Sanjay Gupta, CNN's chief medical correspondent. "In higher doses, it can cause people to go into a coma. It can cause seizures. It can cause something known as hypotonia, where all your muscles just become very flaccid.

The arts and craft beads, aimed at children 4 years and older, have been selling since April at major U.S. retail stores as "Aqua Dots" and in Australia under the name "Bindeez Beads."

Anyone with Aqua Dots at home should throw them out, CPSC spokeswoman Julie Vallese said. The toy was named toy of the year in Australia and recently made Wal-Mart Stores Inc.'s list of top 12 Christmas toys. - CNN

China halts export of bead toys tainted with toxic drug