What is the purpose of maintaining the "chain of custody" during drug testing?

The purpose of maintaining the "chain of custody" during drug testing is fundamental to the integrity and reliability of the testing process. It involves meticulously documenting each step of the specimen's handling from the moment it is collected until the testing is completed. This rigorous tracking ensures that the specimen remains uncontaminated and that it has not been tampered with or altered in any way.

Without a proper chain of custody, there could be questions about who handled the sample, where it was stored, and under what conditions, which could ultimately compromise the reliability of the test results. This process acts as a safeguard against fraudulent practices and helps to uphold the validity and trustworthiness of the drug testing process, especially in legal and workplace environments.

While the other answers provide some relevant aspects of drug testing, none capture the full importance of chain of custody as effectively as maintaining the specimen's integrity and preventing contamination.