The Department of Transportation (DOT) confirmation test is the second of a two-test sequence, and is performed after an employee has a screening test result of .020 or greater. The DOT alcohol test protocol has a very specific procedure for performing an alcohol confirmation test. The operator observes a 15 minute waiting period between the positive screening and the confirmation test to rule out the objection that the screening test result was caused by residual mouth alcohol. The operator must use an EBT that prints results to perform the confirmation test.
For non-regulated testing in general, a confirmation test is performed after a screening test shows the presence of alcohol at or above the cut-off level. Agencies doing non-regulated testing are not required to use .020 as a cut-off level for a positive screening test. Using an EBT for the confirmation test and using a protocol (such as the DOT protocol) that rules out the objection of residual mouth alcohol gives the most defensible results.