DOT Rule 49 CFR Part 40 Section 40.105
Subpart F - Drug Testing Laboratories
§ 40.105 What happens if the laboratory reports a result different from that expected for a blind specimen?
(a) If you are an employer, MRO, or C/TPA who submits a blind specimen, and if the result reported to the MRO is different from the result expected, you must investigate the discrepancy.
(b) If the unexpected result is a false negative, you must provide the laboratory with the expected results (obtained from the supplier of the blind specimen), and direct the laboratory to determine the reason for the discrepancy.
(c) If the unexpected result is a false positive, adulterated, or substituted result, you must provide the laboratory with the expected results (obtained from the supplier of the blind specimen), and direct the laboratory to determine the reason for the discrepancy. You must also notify ODAPC of the discrepancy by telephone (202-366-3784) or e-mail (addresses are listed on the ODAPC website, http://www.dot.gov/ost/dapc ). ODAPC will notify HHS who will take appropriate action.
[65 FR 79526, Dec. 19, 2000, as amended at 73 FR 35971, June 25, 2008]