With 29 states having legal medicinal use of marijuana and nine having legal adult recreational use legal, marijuana and related impairment to function on the job, is a growing topic. Technology that can be used at any time to measure functional impairment is needed to supplement existing biologic measures. Urine does not detect immediate acute use as it takes hours to enter the system. Saliva only measures presence and not impairment. Functional testing that takes only minutes as a screening, is needed.