Okla. Stat. tit. 40, § 556

Any drug or alcohol testing by an employer shall be deemed work time for purposes of compensation and benefits for current employees. An employer shall pay all costs of testing for drugs or alcohol required by the employer. Provided, however, if an employee or applicant requests a confirmation test of a sample within twenty- four (24) hours of receiving notice of a positive test in order to challenge the results of a positive test, the employee or applicant shall pay all costs of the confirmation test, unless the confirmation test reverses the findings of the challenged positive test. In such case, the employer shall reimburse the individual for the costs of the confirmation test.