Warning to Drug Test Cheats...Your Days are Numbered...

To Catch A Cheat

Clinical chemists battle products designed to fool workplace drug tests

Melody Voith

EAGER JOB CANDIDATES who receive an offer of employment might feel as though they have won an Olympic gold medal—especially when they are asked to provide a sample for a drug test. And just like at the Olympics, some test subjects will try to beat the system.

But unlike at the Olympics, where officials test athletes for performance-enhancing substances (C&EN, Aug. 11, page 25), workplace drug tests are performed to identify those whose use of illicit substances may impair their job performance and create liabilities for their employers.

Urine trouble Clinical chemists check for adulterants in drug test samples.According to Amitava Dasgupta, professor of pathology and laboratory medicine at the University of Texas Medical School, Houston, many products are on the market that prospective employees can use to dilute, substitute, or adulterate their test samples. In a talk at the annual meeting of the American Association of Clinical Chemists in Washington, D.C., in late July, he advised laboratory chemists to be vigilant in their pursuit of valid test results. "Toxicologists are smarter than drug users," he said, but they need to know the tricks of the trade.

President Ronald Reagan started the drug-testing arms race in 1986 when he issued an executive order directing federal agencies to achieve a drug-free workplace. Since then, all federal agencies have followed the mandatory guidelines of the Federal Drug-Free Workplace programs administered by the Department of Health & Human Services (DHHS). The guidelines cover testing for marijuana, cocaine, opiates, amphetamines, and phenylcyclohexylpiperidine (PCP).

Many private employers use similar procedures to create a drug-free workplace. In a survey by the Society for Human Resource Management (SHRM), 84% of employers said they conduct preemployment drug testing.

According to R. H. Barry Sample, director of science and technology in the employer solutions division of Quest Diagnostics, a leading test firm, federally mandated test programs currently require the use of urine samples. DHHS has drafted revised regulations that would permit hair and saliva collection, but they are not yet in effect. Almost 90% of drug tests performed by Quest are on urine samples, and saliva tests are the second most common.

Many products that enable cheating target urine tests. Easily found on the Internet, they are marketed under names such as Urine Luck, Ultra Klean Detox Drink, Power Flush, Tinkle, and the Wizzinator.

In his talk Dasgupta described how most methods for cheating on drug tests focus on the first of two testing hurdles—the initial quick-result screening test. The screen is an immunoassay, similar to the at-home drug screens available at many pharmacies. Usually, test administrators at sample collection sites send only nonnegative results to a lab for confirmation testing by gas chromatography/mass spectrometry.

The hundreds of products marketed to help drug users circumvent urine drug tests fall into three main categories: products that are consumed prior to the test, products that are added to the test sample, and devices for smuggling synthetic or borrowed "clean" urine into the testing facility. Toxicologists focus on the first two because, as Sample pointed out, "if it's someone else's urine, there is not a lab test in the world that would tell you that."

CLEANER Workplace Positive drug test results have declined in U.S. workforce

Spectrum Labs' Aqua Clean effervescent tablet, available from detoks.com, is a consumable product that claims to clean the body of drugs and drug metabolites. Like all similar products, it requires the user to drink a vast quantity of water—between 40 and 60 oz—in a short amount of time. Dasgupta's examination of these products has shown they are nothing more than expensive caffeine pills—diuretics that create a lot of urine and dilute drug content to below the screening cutoff values.

IN ADDITION to lowering the concentration of drugs in the urine, however, the excess water also decreases creatinine levels to below 20 mg/dL and specific gravity to less than 1.003, both key indicators of a diluted specimen. Creatinine is a breakdown product of creatine from muscle tissue, and in healthy people it is excreted by the kidneys at a constant rate. Dasgupta recommended creatinine and specific gravity tests on all samples and suggested that lowering drug cutoff values on the screening test would catch most dilutions.

Test takers also try to beat the immunoassays by adding adulterants—including common household chemicals—to their urine sample. Drano drain opener, for example,
[link to pubs.acs.org (secure)]

Last Edited by SPUD on 06/05/2013 07:52 PM