Facts and Fun
Workplace drug screening (pre-employment, random, post-accident, reasonable suspicion) has been part of drug-free workplace policies and programs for years. Such testing is undeniably useful in maintaining a safe and productive workforce. The simple fact that a business conducts such testing will keep some drug users from ever applying. Workers’ comp and other insurance rates are often discounted for businesses that have comprehensive drug free programs. Many employees are even appreciative knowing they will not suffer the potential consequences of a co-worker under the influence.
Having said all that, there are some who believe that the risk of a false positive screen result is too likely and therefore unfair to employees. However, procedures and tests used are such that false positives are quite rare. Mandatory Guidelines for Federal Workplace Drug Testing (also called SAMHSA’s guidelines) are the guidelines used by federal workplaces, federal contractors, and private employers who are not necessarily required to abide by these regulations. They also identify the five substances tested for in drug-testing programs and require the use of drug labs certified by SAMHSA.
The most common method of drug testing is urinalysis. An employee or applicant provides a sample to be tested. Often, precautions are taken, such as putting blue dye in the toilet and turning off the water supply, to prevent adulteration or substitution of specimens so that collection can be completed in privacy without any direct visual observation by another person. However, as you’ll see later in this post, direct observation has become more and more necessary to prevent cheating.
Under SAMHSA’s guidelines, once a sample is provided, it is sent to a certified laboratory. The accuracy of drug tests done by certified laboratories is very high, and this certification applies to the five substances tested for in Federal drug-testing programs and alcohol.
There are certain procedures required by SAMHSA’s guidelines to ensure accuracy and validity of the testing process:
- Chain of Custody: A chain-of-custody form is used to document the handling and storage of a sample from the time it is collected until the time it is tested. It links an individual to his or her sample and is written proof of everything that happens to the specimen at the collection site, in transit, and in the laboratory.
- Initial Screen: The first analysis done on a sample is called an initial screen. This one test alone is not always accurate or reliable; there is a possibility of a false positive. So, in the event that the initial screen is positive, a second confirmatory test is done.
- Confirmation Test: A second, confirmation test (by gas chromatography/mass spectrometry or GC/MS) is highly accurate and provides specificity to help rule out any false positives from the initial screen. For a test result to be reported as positive, the initial screen and confirmation test results must agree.
- Split Sample: A split sample is created when an initial urine sample is split into two. One sample is used for the initial screen and, if positive, the second sample is used for the confirmation test. If there is a positive result, the individual being tested may request the confirmation test be done at a different laboratory.
There are any number of internet sites that warn that ingesting certain common foods or taking OTC meds will result in a false positive. This is highly unlikely. For example, poppy seeds and dextromethorphan have been reported to lead to a false positive result for opiates, and decongestants (ephedrine) have been implicated in causing false positives for amphetamines. The body metabolizes codeine to morphine and both substances may be found upon testing. On the other hand, if benzoylecgonine, the main metabolite of cocaine is detected, the person cannot claim a false positive due to Novocaine administration, or any other "-canine" drug. Benzoylecgonine is only found in nature as a metabolite of cocaine, and there would no other valid reason for it to be present in a drug screen. As previously mentioned, confirmatory testing with GC-MS will identify individual drugs or metabolites in a sample, and almost eliminate the chance for a false positive result.
The argument of inhalation of "passive" smoke from being in a room with people smoking marijuana is also not valid, as the cut-off concentrations for lab analysis are set well above what would occur for passive inhalation.
But still, employees or applicants busted for a positive drug screen still try to snow us (no pun intended), or try to beat the test. People continue to be creative. I’ve collected several examples from colleagues, added a few of my own favorites, and some that anyone can find with a simple Google search. I’ve saved you some time by listing them here! Enjoy.
- Employee picked for a random. Borrowed a sample from a "buddy" and heated it up in the lunchroom microwave. (Ewwww. Just ewwww.)
- Applicant said he wouldn't pass the test because he was an undercover agent for the FBI, and "sometimes you gotta smoke a little with 'em so they believe ya." He was told they didn't care if he was moonlighting but if he couldn't pass the drug test, he wouldn’t be hired. (Creative, but just not gonna fly.)
- Guy had a witnessed test, and was using an external...appendage...to take the test. (Basically a fake so it looked like he was "going" and it held the sample close to his body to hopefully preserve heat.) His mistake was that he used a "device" made for a different race. (Ever heard of the "whizzinator"? Jeez, are ya kidding me??!)
- It was the cookies I ate at a party; I think it was medical marijuana.
- I buy hemp oil and make salad dressing with it. (Yeah, check the ingredients list, it doesn’t contain THC.)
- I ate a bunch of poppy seed muffins.
- I thought I would be positive for pot, not meth! (Think before you speak much?)
- I got it in Canada and it’s legal there. (But not here, right?)
- All of my friends were smoking in a small car; it must be second hand smoke.
- I have to light my wife’s joints for her because she uses medical marijuana and she is too sick to do it herself.
- Someone must have put something in my drink; I swear I would never use drugs.
- One post-accident drug screen, performed by a lab, came back "not consistent with human urine." (I wonder what non-human donated this sample?)
- For those of you who haven’t taken a class in Urine Test Cheating 101, some people put "clean" urine in condoms and store them near their crotch to keep it warm.