What would be cause for rejecting a urine sample for drug of abuse screening?

A urine sample may be rejected for drug of abuse screening when the creatinine level is 5 mg/dL. A low creatinine concentration indicates that the urine sample may be diluted or potentially tampered with. In drug testing, a creatinine level below 20 mg/dL typically raises concerns about the sample's validity, as it suggests that the individual may not have produced a standardized sample for testing. This threshold is important because it helps to ensure the integrity of the test results and ascertain that the sample reflects an accurate representation of the individual's drug use.

In contrast, a temperature of 95°F, a pH of 5.0, and a specific gravity of 1.005 may not necessarily lead to outright rejection. Though temperature can indicate if a urine sample has been tampered with, the range given is still within a plausible range for a legitimate urine sample. A pH of 5.0 is within the acceptable range for urine, and specific gravity at 1.005 may suggest dilute urine but does not confirm tampering in the same definitive manner as a low creatinine level. Thus, it is the very low creatinine concentration that is a standard criterion for rejecting a sample, highlighting the importance of validity testing in drug