Why are two urine specimens (Bottle "A" and Bottle "B") required for drug testing?

The requirement for two urine specimens, often referred to as Bottle "A" and Bottle "B," is fundamentally designed to provide a safeguard for accuracy and fairness in the drug testing process. While the specified answer mentions that it allows the employee to request a second drug screen, it is essential to understand the broader context of this practice.

Using two bottles essentially creates a chain of custody for the samples. Bottle "A" is typically tested initially, and if the results of this test are positive, the employee can then opt to have the second sample, Bottle "B," tested as a confirmation. This process is crucial, as it eliminates the possibility of false positives and supports the integrity of the testing procedure. If any discrepancies arise from the first test, Bottle "B" serves as a backup, ensuring that the employee's rights are protected while upholding the reliability of the test results. This mechanism helps to maintain trust in the drug testing process within the workplace.

While other choices might touch on valid points regarding data collection and regulatory compliance, the core purpose of having two specimens is primarily about fairness and accuracy in testing, with the option for a retest if needed.