[Code of Federal Regulations]
[Title 49, Volume 1]
[Revised as of October 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR40.91]

[Page 605]
 
                        TITLE 49--TRANSPORTATION
 
          SUBTITLE A--OFFICE OF THE SECRETARY OF TRANSPORTATION
 
PART 40--PROCEDURES FOR TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS--Table of Contents
 
                  Subpart F--Drug Testing Laboratories
 
Sec. 40.91  What validity tests must laboratories conduct on primary specimens?

    As a laboratory, when you conduct validity testing under Sec. 40.89, 
you must conduct it in accordance with the requirements of this section.
    (a) You must test each primary specimen for creatinine. You must 
also determine its specific gravity if you find that the creatinine 
concentration is less than 20 mg/dL.
    (b) You must measure the pH of each primary specimen.
    (c) You must test each primary specimen to determine if it contains 
substances that may be used to adulterate the specimen. Your tests must 
have the capability of determining whether any substance identified in 
current HHS requirements or specimen validity guidance is present in the 
specimen.
    (d) If you suspect the presence of an interfering substance/
adulterant that could make a test result invalid, but you are unable to 
identify it (e.g., a new adulterant), you must, as the first laboratory, 
send the specimen to another HHS certified laboratory that has the 
capability of doing so.
    (e) If you identify a substance in a specimen that appears to be an 
adulterant, but which is not listed in current HHS requirements or 
guidance, you must report the finding in writing to ODAPC and the 
Division of Workplace Programs, HHS, within three business days. You 
must also complete testing of the specimen for drugs, to the extent 
technically feasible.
    (f) You must conserve as much as possible of the specimen for 
possible future testing.