Alco-Screen® 02 is so effective that it has been tested and approved by the US Department of Transportation (DOT) for required testing of all transportation and safety sensitive employees for blood alcohol concentrations above the federally mandated zero tolerance level of 0.02%. Alco-Screen® 02 is a simple one-step saliva screening test that works in a clean, non-invasive manner and provides results within 4 minutes. Simply wet the test pad with saliva. Development of a line on the test pad within 4 minutes indicates a blood alcohol concentration exceeding 0.02%. This simple, highly effective test allows you to tell if the individual being tested is under the influence of alcohol.