"At this time, forty-six (46) states and the federal government have scheduled one or more synthetic cannabinoids by statute or regulation and twenty-nine (29) states have some form of the generic language. Of the four states that have not scheduled one or more of the synthetic cannabinoids, Louisiana and Nebraska include the generic language. The only two states that have not yet scheduled any of the synthetic cannabinoids or the generic language are Maryland and Rhode Island. Maryland had four bills pending this legislative session, but was unable to get legislation passed before the session adjourned. There is still a regulation pending in Maryland that would schedule certain cannabinoids. The District of Columbia also has legislation pending. Rhode Island, however, does not have anything pending at this time."
Gray, Heather, An Introduction to Synthetic Drugs, National Alliiance for Model State Drug Laws. Santa Fe, NM: June 2012.