What is a chain of custody?

• A. A log of the transport route for the samples
• B. A record of all laboratory instruments used
• C. A record of each person who handles the sample from collection to lab analysis
• D. A policy document describing how samples are destroyed

Answer: (C)

Chain of custody is the documented trail that shows every person who has handled the sample from the moment it is collected through to the laboratory analysis. It records who took possession, when, and under what conditions, with signatures or initials and timestamps, creating an unbroken chain that preserves the sample’s identity and integrity. This accountability is essential so the lab results can be trusted and defended in audits or regulatory reviews, especially in lead clearance where legal and compliance standards hinge on proving the exact origin and handling of the samples.

A log of the transport route might help track movement, but it doesn’t capture who actually touched or controlled the sample at each step. A record of laboratory instruments used focuses on equipment, not people responsible for the sample’s custody. A policy about how samples are destroyed describes end-of-life handling, not the ongoing custody from collection to analysis.