I believe the urine test also screens for diabetes. Side note...marijuana has harmful effects and is not some miracle plant...I am sure you know that but I dont like it when people put out the perception that it is no big deal and it can not hurt you. If you really want to be safe maybe you could buy your own screen tests...it may be expensive as hell but that way you could screen yourself everyday before going into work...I do not condone your actions but at least you would know for a fact if you were risking not only yourself but others around you.