What Is a Split Specimen Test, and Who Pays for It?

At a DOT urine collection, the specimen is divided into two bottles. Bottle A, the primary specimen, is tested by the laboratory. Bottle B, the split specimen, is sealed and stored. If the primary result is verified as positive, adulterated or substituted, the employee can ask for Bottle B to be tested at a second laboratory. The rules are in 49 CFR 40.171 through 40.187. Split specimen rules also apply to oral fluid collections. The handling of both bottles is covered in drug testing chain of custody.

How the employee requests it. After the MRO notifies the employee of a verified positive result or a refusal because of adulteration or substitution, the employee has 72 hours from that notice to request a split test. The request may be verbal or in writing (49 CFR 40.171(a)). There is no split test for an invalid result.

Late requests. An employee who misses the 72 hours can give the MRO information showing that serious injury, illness, lack of actual notice, inability to reach the MRO or other circumstances unavoidably prevented a timely request. If the MRO finds a legitimate reason, the split test goes forward (49 CFR 40.171(b)).

What the MRO does. On a timely request, the MRO immediately gives written notice to the first laboratory to send the split specimen to a second HHS-certified laboratory, and documents the date and time of the request (49 CFR 40.171(c)).

Who pays. The employer is responsible for making sure the MRO and both laboratories perform their functions in a timely manner (49 CFR 40.173(a)). The employer may not condition the split test on the employee paying or agreeing to reimburse. If the employee cannot or will not pay, the employer pays so the test happens on time (49 CFR 40.173(b)). The employer may seek payment or reimbursement afterward. Part 40 takes no position on who bears the final cost (49 CFR 40.173(c)).

Possible outcomes. Section 40.187 sorts split results into five categories:

• Reconfirmed. The positive or refusal becomes the final result.
• Failed to reconfirm. The test is cancelled, and the MRO informs ODAPC. The MRO directs an immediate recollection under direct observation when the split failed to reconfirm because substitution criteria were not met and the split creatinine is 2 to 5 mg/dL, or when the primary specimen was also reported invalid (49 CFR 40.187(b)).
• Failed to reconfirm and split invalid, adulterated or substituted. The outcome depends on the combination. An invalid split leads to cancellation and an observed recollection (49 CFR 40.187(c)).
• Partial reconfirmation. When the split reconfirms one or more but not all of the primary results, the employer acts on the reconfirmed results (49 CFR 40.187(d)).
• Split not available. The test is cancelled and an immediate observed recollection follows, with no advance notice to the employee.

Removal does not wait. The employee stays out of safety-sensitive duties while the split is pending (49 CFR 40.23(a)).