Frequently a substance found at a port of entry, waste site, laboratory triage facility, or even in a hazardous materials emergency will be labeled and purportedly identified. But law enforcement and other first responders cannot take this claim at face value, as the accuracy is not confirmed and must be verified. A comprehensive handbook for on-the-spot investigations, Field Confirmation Testing for Suspicious Substances provides those who confront suspicious substances with the tools to confirm or deny a labeled identity.