Accurate reporting starts at the beginning with the collection of the sample and a properly completed Chain of Custody (COC) form. The COC is a hard copy trail of the history of the sample collection including customer information, testing to be performed, and the date and time of sampling. The COC ensures that hold times are met and verifies the party in possession of the sample at all times. An electronic and hard copy version of the COC is retained at our offices. Chain of Custody (PDF)