PHMSA Response Letter

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Office of Drug Enforcement and Program Compliance

49 CFR Part 40 Interpretation

Question: Does the medical review officer (MRO) have to verify each drug when the laboratory reports a multiple positive drug test results for the same individual under the Department of Transportation (DOT) drug and alcohol rule.

Guidance: Section 40.33(a) states "Medical review officer shall review confirmed positive results." The DOT drug rule requires analysis of urine for five drugs. Multiple drug positive results for the same specimen (donor) require the MRO to verify each reported drug to determine if there is a medical explanation for each positive result. Additionally, the DOT drug and alcohol management information system requests information on multiple drug results (for each individual). The intent is to capture this information.

However, in the preemployment process, it would appear that with the employer's consent, the medical review officer (MRO) may report a verified positive result for one drug out of several laboratory positive results (for one individual) without continuing to seek verification for the other drugs reported by the laboratory. The MRO may need to use his/her professional judgement to determine if verification of the other drugs may be accomplished expeditiously. Regardless of the number of drugs that are reported as verified for one individual, that individual cannot perform safety-sensitive work until he/she provides a urine specimen that is negative.

In the case where the MRO verifies and reports only one drug, the other drugs should not be reported to the employer if they have not been verified. The MRO may document these unverified positive results in his/her records as unverified and unreported results.