The story

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. Read full article »

CNN's Janine Brady, Jason Carroll, Laura Dolan, Julie O'Neill and Leslie Wiggins contributed to this report.