How Does a Split Specimen Test Work after a Positive DOT Drug Test?

Under 49 CFR 40.171, an employee who has been notified by the Medical Review Officer (MRO) of a verified positive drug test result, or of a refusal because of adulteration or substitution, has 72 hours from the time of notification to request a test of the split specimen.

The rule states that the request may be verbal or in writing. When a timely request is made, the MRO gives written notice to the laboratory that tested the primary specimen, which forwards the split specimen to a second HHS-certified laboratory.

Section 40.171 also states that there is no split specimen testing for an invalid result. If the 72 hours pass, the employee may give the MRO information showing that serious injury, illness, lack of notice or other circumstances prevented a timely request, and the MRO may direct the test if the reason is legitimate.

The split request goes to the MRO, and the split test is done by a laboratory. MROs and laboratories are both listed in the MyDrugTesting.com directory. The way the specimen is divided at collection is covered in How Is a DOT Urine Specimen Split and Sealed?.