The purpose of the public interest exclusion (PIE) is to protect transportation employers and employees from serious noncompliance with DOT drug and alcohol testing rules by ensuring that employers conduct business only with responsible service agents.
The DOT uses PIEs to exclude any service agent from participating in its drug and alcohol testing program that by serious noncompliance has shown that is it not currently acting in a responsible manner. The process by which a service agent is issued a PIE is found in Subpart R of Part 40.
The DOT maintains a document called “List of Excluded Drug and Alcohol Service Agents” which lists those agents who cannot be used in DOT drug and alcohol programs. This document can be found at the DOT website.