An Alcohol Screening Device (ASD) measures alcohol concentration in the saliva or the breath. ASDs that meet National Highway Traffic Safety Adminstration (NHTSA) specifications for precision and accuracy are placed on a Conforming Products List (CPL) for Alcohol Screening Devices. The CPL of Alcohol Screening Devices currently includes disposable saliva and breath alcohol tests, and several battery operated breath alcohol testers.
Because the accuracy standards for ASDs are not as strict as for EBTs, and because most Alcohol Screening Devices are not capable of printing results, DOT regulations state that ASDs may only be used as a screening test.
When performing DOT alcohol testing a person must be certified either as a Screening Test Technician (STT) or a Breath Alcohol Technician (BAT) to use an Alcohol Screening Device.