Why Drug Testing Doesn't Always Work

Drug testing has changed little in the fifteen years that employers started requiring drug screening as a condition of employment.

The pee in the cup method is still most prevalent, says Gary Hanley, executive vice president of USA-FACT, an employment screening company.

While hair follicle and saliva testing are now possible, for the most part urine is done because it's the least expensive. A typical urine test is about $25 to $32. Hair follicle testing costs about $75.

Testing can be performed as part of the application process before an offer of employment is made. Some companies test after an offer of employment is made, but before the employee commences work. Still others require testing shortly after the employee starts the job on the condition that employment is contingent upon successful completion of the drug and/or alcohol test, according to USA-Fact, of Riverside, Calif.

As when companies first started testing their candidates, testing remains controversial. Critics contend that it's too easy to cheat ones way into a clean bill of health and, more dangerously, innocent people are hurt by "false positive" results.

Typically, companies will test for five major categories of drugs: amphetamines, cannabinoid (marijuana), cocaine, opiates and phencyclidine, which are adulterates meant to detect if a person is "cheating" on the test. (More on that later.)

Urine testing cannot actually determine when a drug was used. It can only detect the "metabolite" or inactive, leftover traces of previously ingested substances. For the most part, the tests can only detect traces of drugs ingested two to four days prior to the test, Hanley says. The exception is marijuana, which can be detected for 30 days or greater, depending on the individual.

The way it works is once the applicant urinates into a cup, a lab technician will test the sample and send the results by Federal Express to USA-FACT. Hanley says he reports the results to employers. It is done this way to avoid the possibility of discrimination, he says. Urine tests can be used to determine conditions that unscrupulous employers might use to reject applicants, such as depression, epilepsy, or diabetes, he says. Tests can also determine if a woman is pregnant, but finding out through testing is against the law.

Because it's possible to use "detoxifying products" to cleanse urine, USA FACTS and other companies test for adulterants. If someone tests positive for using an adulterant, it's up to the company to decide what to do about it. Some employers will tell the person to clean up and take the test again. Some will rescind a job offer.

"From my experience with clients, a lot of it is dependent on the economic environment," Hanley says. "If they're really in need of the employee they'll be lax versus what they'll do in a slow economy when there's plenty of applicants and they tend to be a little more strict."

Companies that produce detoxifying products, such as Cinncinati-based Spectrum Labs, however, contend that their urine additives are "undetectable" by the labs.

The tests aren't foolproof. Certain prescription and non-prescription drugs have been known to show up as illegal drugs. Poppy seeds too are a problem because they contain a minute amount of opium and tests are sensitive. That's why companies employ a Medical Review Officer (MRO) who will review results and determine whether legitimate drugs or poppy seeds were read wrongly, Hanley says.

One outspoken drug-testing critic contends that MROs serve as "rubber stamps." Hundreds of false positives are the result of incompetent reading of test results and faulty test processes, he says. He also says the tests could be more reliable but companies don't want to spend the money for more accurate tests.

"Drug users are passing [because of adulterates] and non-drug users are the ones walking in and failing because their over-the-counter medications, prescription medications or herbs can cause false positives," charges Kent Holtorf, a medical doctor and author of "Ur-Ine Trouble: How Drug Users Are Passing and Nonusers Are Failing."

Holtorf, an internationally known drug-testing expert, says he gets 10 to 20 calls a day from people claiming they lost jobs or were disciplined because of false positive tests. The largest lawsuit he's helped a client win was $800,000 because of a false positive test caused by poppy seeds.

Kenneth Collins, a behavioral health care consultant, says that testing is in fact reliable. Other than poppy seeds and prescription medication, there's not much that would cause a positive test result, he says. And government certified labs have had years to "de-bug" their chain of custody processes.

"I think that there are a far greater number of drug users who pass pre-employment tests, for a variety of reasons, than there are nonusers who wind up with false positives," he says.