Employer Responsibilities Under the New Part 40: What You Need to Know

April 22, 2025

Ophthalmologist's Department

The Department of Transportation (DOT) recently clarified employer responsibilities in the preamble of the updated Part 40 regulations. These updates address how discipline, termination, and arbitration relate to drug and alcohol testing violations. Here’s a clear breakdown of what employers need to understand.

Discipline and Termination Decisions Are the Employer’s Responsibility

DOT emphasizes that decisions about disciplining or terminating an employee are left to the employer’s discretion or handled through labor-management agreements.

  1. If an employer’s policies or agreements delegate decisions to an arbitrator, the arbitrator’s ruling will determine the employment outcome.
  2. For example, an arbitrator may decide a test shouldn’t have been conducted or was mishandled, leading to reinstatement or back pay.

What Arbitration Cannot Do: Overturn Test Results

Even if arbitration influences employment decisions, it cannot change or erase a DOT violation.

  1. A positive drug or alcohol test remains a violation, regardless of any employment-related rulings.
  2. The employee must still complete the Substance Abuse Professional (SAP) process before returning to safety-sensitive duties.
  3. Violations cannot be removed through arbitration, grievances, or state court decisions.

DOT’s Stance on Refusals

Refusal to test is considered a willful violation of DOT regulations.

  1. Even if employment actions are reversed, the refusal itself remains on record.
  2. The employee is still required to complete the SAP process to be eligible for safety-sensitive duties.

Why This Matters for Employers

Understanding these distinctions is key to remaining compliant:

  1. Personnel vs. Violation: Arbitration may impact employment status but does not erase a violation.
  2. SAP Process is Non-Negotiable: Reinstated employees must still complete the SAP process.
  3. Auditor Attention: DOT auditors are closely reviewing cases where arbitrators attempt to override DOT testing rules. Employers must follow federal requirements regardless of arbitration outcomes.

Final Thoughts

DOT’s updated guidance reinforces a clear boundary: employment decisions may be flexible, but violations are not. Employers must ensure that any employee with a DOT violation completes the necessary return-to-duty process, even if they are reinstated. This ensures compliance, supports safety, and upholds the integrity of federal regulations.

Karishma Sarfani

Karishma is a Qualified Substance Abuse Professional (SAP) with a background in mental health and substance abuse counseling, holding credentials as an MS, LCDC, ICADC, CADC II, CSAC, CASAC II, LPC, and EMDR-trained therapist. Inspired by personal experiences with addiction and mental health challenges in her community, she has dedicated her career to supporting individuals on their journey to recovery and success.