The United States Department of Transportation (DOT) defines the Substance Abuse Professional (SAP) as an individual who evaluates employees who have violated a DOT drug and alcohol regulation and makes recommendations concerning education, treatment, follow-up testing and aftercare.
The DOT requires that any employee whose position falls under the DOT and violates the DOT rules & regulations for drug & alcohol on a pre-employment, random, reasonable suspicion, post-accident screening must be referred to a certified Substance Abuse Professional, even if the employee is terminated. This requirement is per 49 CFR Part 40, Subpart O.
It is important to understand that the SAP is an advocate for neither the employee nor the employer. The function of the SAP is to protect the public interest.