What criteria do laboratories use to establish that a specimen is adulterated? § 40.95
(a) As a laboratory, you must consider the primary specimen to be adulterated if you determine that—
(1) A substance that is not expected to be present in human urine is identified in the specimen;
(2) A substance that is expected to be present in human urine is identified at a concentration so high that it is not consistent with human urine; or
(3) The physical characteristics of the specimen are outside the normal expected range for human urine.
(b) In making your determination under paragraph (a) of this section, you must apply the criteria in current HHS requirements or specimen validity guidance.