(For example, if the test confirmed
the presence of codeine, and the employee admits to unauthorized use of hydrocodone, you must not verify the test positive for codeine.
(b) In the absence
of 6 - AM, if the laboratory confirms the
presence of either morphine or
codeine at 15,000 ng / mL or above, you must verify the test result positive unless the employee presents a legitimate medical explanation for the
presence of the drug or drug metabolite in his or her system, as in the case
of other drugs (see § 40.137).