I do not know too much about the stuff. I read it is made in Korea and China mainly. I do not think there has been any research (especially long term) on this stuff. I would not want to expose ant fetus to anything we know so little about, especially when it states clearly on the package "Not for human consumption"
My boyfriend is on house arrest and smokes the "incense" every day. When they drug test him at probation, he comes up clean every time. It does NOT show up in the standard drug tests. Even when she checks for all known illegal drugs.