What is “adulteration” and how do testers try to adulterate a drug test?

Written by Lucas Kibby

Adulteration is defined as purposefully tampering a specimen with the intent of altering the test results that are feared will be positive. Adulterants may cause “false negative” results by either interfering with the test and/or destroying the drug metabolites in the specimen.

In urine tests, the most common type of drug test method, dilution may be used to produce false negative drug test results. To help rule out deliberate adulteration, it is best to request “directly-observed” drug tests. All hair strand and oral fluid “saliva” drug tests are directly observed.

There are certain characteristics of urine that are easy to measure in order to determine adulteration such as temperature, specific gravity and pH. Below are these common characteristics in urine drug tests that are regularly measured to test for cheating a drug test:

Temperature: Some adultered samples are way too cold or way to hot due to being “warmed up” with hand warmers or microwaves (which can cause urine sample to explode). All valid samples range from 90-100 degrees.

Creatinine: An amino acid contained in muscle tissue and found in urine. The lab may find a low creatinine lab value. There are two reasons for this. Either the person providing the sample diluted their urine by consuming excessive water just prior to testing, or water was added to the urine sample.

pH (Acidity): Subjects may also attempt to add certain enzymes to the urine sample to affect stability, but this often changes the pH, which is also tested. Normal pH levels should be in the range of 4.0 to 9.0.

Oxidants: Bleach, hydrogen peroxide and Pyridinium Chlorochromate (“UrineLuck”).

Specific Gravity (Dilution): Creatinine levels are often used in conjunction with specific gravity to determine if samples have been diluted. To help avoid this problem, the collection site or on-site collector may color the toilet water blue to prevent the sample being diluted with water from the toilet. Normal levels for specific gravity will range from 1.003 to 1.030.

Nitrates: Tests for commonly used commercial adulterants such as “Klear” or “Whizzies.”

Glutaraldehyde: This adulterant may cause false-negative drug test results by disrupting the enzyme used in some immunoassay tests and not normally found in human urine.

Remember, in some labs, patients who receive a positive result may have the option to pay for an independent re-test of the urine sample that was originally submitted. A new urine sample is not allowed for the re-test as the drug in question may be out of the system by that time.

Do you have a company drug and alcohol policy yet? If so, when was the last time you reviewed your policy?

The policy needs to be clear on what the consequences are if an employee refuses to test, is caught cheating a test, or if the results come back positive. Knowing these consequences can help deter the inappropriate use of drugs and alcohol in the workplace.