While synthetic marijuana is already banned statewide, some new chemical compounds aren't illegal in Chicago yet. That's because when one kind is banned usually a similar drug comes out.
Chicago's City Council is proposing a measure to ban the sale of substance that mimics THC, the active ingredient in pot. Under the measure, any person who sells or has the banned substances oculd be fined between $500 and $1,000.
Attorney General Lisa Madigan is praising the city council's proposal. She said synthetic marijuana is dangerous. It causes vomiting, agitation and sometimes seizures.
"Most parents, most adults don't know about this - but the kids do. And the kids think because they can purchase these substances in stores, well it must be safe. And nothing could be further from the truth," Madigan said.
The substance can be found under the name "K2" or "spice" and is sometimes marketed as potpourri or herbal incense.
The Illinois Poison Center reported it's increasingly getting emergency room calls about people getting sick from smoking synthetic marijuana. In 2010 the center received 70 calls, and so far this year they've received 304 calls.