49 CFR § 40.15 - May an employer use a service agent to meet DOT drug and alcohol testing requirements?
(a) As an employer, you may use a service agent to perform the tasks needed to comply with this part and DOT agency drug and alcohol testing regulations, consistent with the requirements of Subpart Q and other applicable provisions of this part.
(b) As an employer, you are responsible for ensuring that the service agents you use meet the qualifications set forth in this part (e.g., § 40.121 for MROs). You may require service agents to show you documentation that they meet the requirements of this part (e.g., documentation of MRO qualifications required by § 40.121(e)).
(c) You remain responsible for compliance with all applicable requirements of this part and other DOT drug and alcohol testing regulations, even when you use a service agent. If you violate this part or other DOT drug and alcohol testing regulations because a service agent has not provided services as our rules require, a DOT agency can subject you to sanctions. Your good faith use of a service agent is not a defense in an enforcement action initiated by a DOT agency in which your alleged noncompliance with this part or a DOT agency drug and alcohol regulation may have resulted from the service agent's conduct.