An invalid test result is acceptable except in the following cases:   

·         The employer needs a negative test result (DOT and Consortium Pre-Employment, Return-to-Duty)

·         The MRO has instructed a recollection and/or medical evaluation

Return-to-Duty and SAP referrals are relevant to non-negative results so, if an employee is restricted due to an invalid test result that employee should not be subject to an RTD program (unless the client’s corporate policy indicates otherwise).