Nelly Miles, the GBI's chemistry section manager, said, "They changed the molecular structure altogether." The side effects of the new composition can be worse, she said.
Chase's Law, named after a Fayette County teen who drowned in his parent's hot tub after smoking synthetic pot, was authored in part by GBI agents to prevent future chemical modifications by manufacturers.
"They essentially altered the basic structure and started all over again," said state Sen. Buddy Carter, R-Pooler, who authored the bill outlawing its sale.
Convenience store owners recently received notification from the manufacturers that they could put the product back on the shelves, Carter said. Apparently, many have resumed selling the product knowing they can't be held criminally liable.
The substance, composed of plant material and sprayed with chemicals that mimic THC, the active ingredient in marijuana, sells from $5 and it marketed as incense or potpourri. Though sold with a label warning it's "not for human consumption," its target audience has long known it's used for getting high.
And it remains popular, despite the ill-fated ban, said Gaylord Lopez, director of Georgia Poison Control.
"Unfortunately, we're seeing roughly the same pace of reported cases this year as we did in 2011," Lopez said. There were 319 cases reported last year compared to just 74 in 2010.
Lopez said he's heard anecdotally that merchants "can't keep the stuff on the shelves."
It remains attractive to users, he said, because it provides a greater high than marijuana, remains largely undetected by drug tests and is readily available.
Referring to it as marijuana actually may be a disservice since the chemical variety is much more dangerous, experts say.
Side effects include a rapid heart beat, tremors, "seizure-like activity" and a loss of consciousness -- "things that don't typically happen from marijuana use," Lopez said. "This is definitely causing headaches in emergency rooms across the state."
Last September, a Woodstock paint store manager was arrested after getting into a violent confrontation after smoking synthetic cannabis.
Patrick Bynum, 33, allegedly pulled a gun on a female friend, who also admitted to smoking the chemical, and then attempted to carjack several passing vehicles. It took three officers and repeated hits with a stun gun to subdue him, police said.
Carter said legislators will revisit the ban in the next session.
"Make no mistake about it, they are testing our resolve," the state senator said. "It's going to be very difficult to keep up with these guys, but we're going to do whatever it takes to win the battle."