Ignorance of the law is no excuse
2 years for posession of GBL, like acetone free nail polish?
The net is going to cast very wide to include the bulk chemicals used to produce synthetic drugs like Spice, as they will start altering them to avoid whatever the new law lists as illegal.
Esepcially if like GBL they can find something that metabolises into something else, or where the user performs some final process like mixing with alcohol or some common drugs from the chemist.
It may just create a new art of drug making that results in something far worse or addictive, like glue sniffing.