
Understanding Split Specimen Testing in Drug Screening
Understanding Split Specimen Testing in Drug Screening
Drug testing is a common practice in various industries, mandated by the Department of Transportation (DOT) among others, to ensure workplace safety and compliance with regulations. In many cases, a donor's specimen is split to safeguard their interests in the event of a false positive result or if they seek a second opinion.
A false positive can occur due to various factors such as errors in the testing process, faulty equipment, or other unforeseen circumstances. Split specimen testing involves dividing the donor's sample into two vials, with one vial being tested initially. The results typically fall into four categories: Negative, Negative-Dilute, Positive, and Positive-Dilute.

If the initial test returns a negative result, there is usually no need for further testing of the split specimen. However, in the case of a positive result for federally mandated tests, a Medical Review Officer (MRO) must conduct a thorough review. This involves contacting the donor to explore alternative explanations for the positive result, such as prescribed medications. For non-federally regulated tests, it is advisable to involve an MRO in reviewing the results with the donor, as outlined in your drug testing policy.
During the donor interview process, if a legitimate explanation is found for the initial positive result, the MRO informs the donor that the test will be reported as negative to the employer, thereby protecting the donor's privacy.
Split specimen testing is only initiated if the donor disputes the positive result. In such cases, the MRO informs the donor that the split specimen (Bottle B) is available for testing at another laboratory for confirmation. Want to become certified, enroll today!
The Split Specimen Testing Process and Timeline
For all positive results, the MRO reports the initial positive to the employer, as required by regulations. If the donor agrees to the split specimen testing, the process may take an additional week to obtain the final result.
After the split specimen is tested at a second laboratory, there are five possible outcomes, with the first two being the most common:
The laboratory reconfirms one or more of the primary specimen results:
The MRO reports the reconfirmed result(s) to the Designated Employer Representative (DER) and the employee.
In the case of reconfirmed positive tests, the positive result stands.
In the case of reconfirmed adulterated or substituted results, the refusal to test is considered the final result.
In the case of a combination of positive and refusal to test results, both are considered the final result.
The laboratory fails to reconfirm all primary specimen results:
The MRO informs the DER and the employee that the test must be cancelled.
The MRO notifies the Office of Drug and Alcohol Policy and Compliance (ODAPC) of the failure to reconfirm.
Depending on the circumstances, the MRO may direct the immediate collection of another specimen under direct observation.
Understanding the split specimen testing process is essential for both employers and employees involved in drug screening procedures. Compliance with DOT regulations ensures fairness and accuracy in the testing process, ultimately promoting safety and integrity in the workplace.