Illinois Sen. Mark Kirk publicly called for the Chinese government to do more to stop the drug from entering the U.S. Monday.

The request comes in the aftermath of an NBC 5 investigation which demonstrated the near-constant flow of synthetic marijuana through the postal facility at O’Hare International Airport.

“I would note that you have no idea what dangerous poison is in this stuff,” Kirk said Monday, following a tour of the Customs and Border Protection post inside the U.S. Postal Service facility at O’Hare. “We want to make sure as many citizens don’t die from this stuff as possible.”

Sen. Kirk Demands Chinese Stop Flow of Synthetic Pot